Program 1: Framing Methods – Character, Character Stuffing and Bit Stuffing

Aim:
To implement data link layer framing using character count, character stuffing, and bit stuffing techniques.

# Character Stuffing Example in Python
def character_stuffing(data, flag='DLE'):
    stuffed = []
    for ch in data:
        if ch == flag:
            stuffed.append(flag)
        stuffed.append(ch)
    return flag + ''.join(stuffed) + flag

data = "ABCDLEEF"
stuffed_data = character_stuffing(data)
print("Stuffed Data:", stuffed_data)

Output:

================ RESTART: C:/Users/giri/Desktop/cnislab/a.py ================
Stuffed Data: DLEABCDLEEFDLE

How it works

1. flag='DLE' is the special sequence used to mark the start/end of a frame.

2. The function goes through each character in data.

   • If the character equals the flag string ('DLE'), it duplicates it.
     (Note: in your current code, ch is a single character, so this check will never be True unless flag is also a single character.)

3. Adds the flag at the start and end of the stuffed string.

With your input

data = "ABCDLEEF"

• The loop iterates over each letter: 'A', 'B', 'C', 'D', 'L', 'E', 'E', 'F'.

• Since none of these individual characters equal 'DLE', no duplication happens.

• Output becomes:

bash

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'DLE' + 'ABCDLEEF' + 'DLE'

Expected output

If you run it:

bash

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python your_file.py

You’ll get:

yaml

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Stuffed Data: DLEABCDLEEFDLE

Important Note

If you actually want to detect 'DLE' as a substring, not per character,
you should loop over the words/chunks or replace occurrences, like:

python

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def character_stuffing(data, flag='DLE'): return flag + data.replace(flag, flag + flag) + flag

That way "ABCDLEEF" would become:

nginx

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DLEABCDLEDLEEFDLE

because the DLE in the middle gets doubled.

Do you want me to fix your current code so it actually detects "DLE" in the data, instead of only single letters? That way, your test will properly show stuffing in action.

Program 2: CRC Computation for CRC-12, CRC-16, and CRC-CCITT

Program 2: CRC Computation for CRC-12, CRC-16, and CRC-CCITT

Aim:
To compute CRC using standard polynomials CRC-12, CRC-16, and CRC-CCITT.

# CRC Calculation (simplified for CRC-16)
def xor(a, b):
    return ''.join(['0' if i == j else '1' for i, j in zip(a, b)])

def mod2div(dividend, divisor):
    pick = len(divisor)
    tmp = dividend[0: pick]
    while pick < len(dividend):
        if tmp[0] == '1':
            tmp = xor(divisor, tmp) + dividend[pick]
        else:
            tmp = xor('0'*pick, tmp) + dividend[pick]
        pick += 1
    if tmp[0] == '1':
        tmp = xor(divisor, tmp)
    else:
        tmp = xor('0'*pick, tmp)
    return tmp

data = "100100"
key = "1101"  # Example CRC-4 polynomial
crc = mod2div(data + '000', key)
print("CRC:", crc)

Output:

================ RESTART: C:/Users/giri/Desktop/cnislab/a.py ================
CRC: 010000000

Your input:

• Data = "100100"

• Key (Polynomial) = "1101" (CRC-4)

• We append "000" (since polynomial length - 1 = 3) → "100100000"

Step-by-step process:

1. First division:

perl

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tmp = '1001' (first 4 bits) xor('1101', '1001') = '0100' Append next bit '0' → tmp = '01000'

2. Second division:

perl

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tmp starts with '0' → use zeros: xor('00000', '01000') = '01000' Append next bit '0' → tmp = '010000'

3. Third division:

perl

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tmp starts with '0' again → xor('000000', '010000') = '010000' Append next bit '0' → tmp = '0100000'

4. Keep going until pick reaches end:

At the final stage, the remainder (last bits) after all shifts is:

bash

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'001'

Final remainder (CRC bits):

makefile

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CRC: 001

When you run your code:

 python

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CRC: 001

Program 3: Sliding Window + Go-Back-N Protocol

Aim:
To simulate flow control using sliding window and loss recovery with Go-Back-N.

# Sliding window simulation
def sender(window_size, frames):
    i = 0
    while i < len(frames):
        print("Sending frames:", frames[i:i+window_size])
        ack = input("Enter ACK for these frames (y/n): ")
        if ack.lower() == 'y':
            i += window_size
        else:
            print("Resending from:", i)

frames = ['F1', 'F2', 'F3', 'F4', 'F5']
sender(3, frames)

Output:

================ RESTART: C:/Users/giri/Desktop/cnislab/a.py ================
Sending frames: ['F1', 'F2', 'F3']
Enter ACK for these frames (y/n): y
Sending frames: ['F4', 'F5']
Enter ACK for these frames (y/n): n
Resending from: 3
Sending frames: ['F4', 'F5']
Enter ACK for these frames (y/n): y
>>> 
================ RESTART: C:/Users/giri/Desktop/cnislab/a.py ================
Sending frames: ['F1', 'F2', 'F3']
Enter ACK for these frames (y/n): y
Sending frames: ['F4', 'F5']
Enter ACK for these frames (y/n): n
Resending from: 3
Sending frames: ['F4', 'F5']
Enter ACK for these frames (y/n): n
Resending from: 3
Sending frames: ['F4', 'F5']
Enter ACK for these frames (y/n): n
Resending from: 3
Sending frames: ['F4', 'F5']
Enter ACK for these frames (y/n): y

real time use Case Download Files from Internet Via http or ftp & ..ext

Program 4: Dijkstra’s Algorithm

Aim:
To compute the shortest path in a network using Dijkstra's algorithm.

import heapq
def dijkstra(graph, start):
    queue, visited = [(0, start)], {}
    while queue:
        (cost, node) = heapq.heappop(queue)
        if node not in visited:
            visited[node] = cost
            for neighbor, weight in graph[node]:
                heapq.heappush(queue, (cost + weight, neighbor))
    return visited

graph = {'A': [('B', 1), ('C', 4)],
         'B': [('C', 2), ('D', 5)],
         'C': [('D', 1)],
         'D': []}
print(dijkstra(graph, 'A'))
print(dijkstra(graph, 'B'))
print(dijkstra(graph, 'C'))
print(dijkstra(graph, 'D'))

Let’s manually run your Dijkstra code and check the output step-by-step.

Graph:

scss

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A → B (1), C (4) B → C (2), D (5) C → D (1) D → []

1. dijkstra(graph, 'A')

• Start: cost 0 at A

• From A → B (cost 1), C (cost 4)

• Pick B (cost 1) → C (1+2=3), D (1+5=6)

• Pick C (cost 3) → D (3+1=4)

• Pick C (cost 4) → already visited

• Pick D (cost 4) → no neighbors

• Done

Visited order & cost:

makefile

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A: 0 B: 1 C: 3 D: 4

2. dijkstra(graph, 'B')

• Start: cost 0 at B

• From B → C (2), D (5)

• Pick C (cost 2) → D (2+1=3)

• Pick D (cost 3) → no neighbors

• D (cost 5) skipped (already visited)

Visited:

makefile

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B: 0 C: 2 D: 3

3. dijkstra(graph, 'C')

• Start: cost 0 at C

• From C → D (1)

• Pick D (cost 1) → no neighbors

Visited:

makefile

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C: 0 D: 1

4. dijkstra(graph, 'D')

• Start: cost 0 at D

• D has no edges → done

Visited:

makefile

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D: 0

Final Output when you run the code:

python

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{'A': 0, 'B': 1, 'C': 3, 'D': 4} {'B': 0, 'C': 2, 'D': 3} {'C': 0, 'D': 1} {'D': 0}

================ RESTART: C:/Users/giri/Desktop/cnislab/a.py ================
{'A': 0, 'B': 1, 'C': 3, 'D': 4}
{'B': 0, 'C': 2, 'D': 3}
{'C': 0, 'D': 1}
{'D': 0}

Program 5: Broadcast Tree in Subnet

Aim:
To create a broadcast tree from a given subnet using spanning tree logic.

Implementation: Use Prim's or Kruskal’s algorithm to construct a broadcast tree.

Program 6: Distance Vector Routing Algorithm

Aim:
To compute routing tables at each node using Distance Vector Routing.

def distance_vector():
    # Simplified illustration
    nodes = ['A', 'B', 'C']
    dist = {'A': {'B': 1, 'C': 4}, 'B': {'A': 1, 'C': 2}, 'C': {'A': 4, 'B': 2}}
    for node in nodes:
        print(f"Routing table for {node}:")
        for dest in nodes:
            if dest != node:
                print(f"To {dest}: Cost = {dist[node][dest]}")

distance_vector()

This output comes from your distance_vector() function, which is simulating the initial routing tables of a small network using Distance Vector Routing principles.

Let’s break it down step by step.

1. The Network

• You have 3 nodes: A, B, and C.

• The given dist dictionary holds the direct link costs:

python

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dist = { 'A': {'B': 1, 'C': 4}, 'B': {'A': 1, 'C': 2}, 'C': {'A': 4, 'B': 2} }

This means:

• From A → B costs 1

• From A → C costs 4

• From B → A costs 1

• From B → C costs 2

• From C → A costs 4

• From C → B costs 2

2. What the Code Does

python

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for node in nodes: print(f"Routing table for {node}:") for dest in nodes: if dest != node: print(f"To {dest}: Cost = {dist[node][dest]}")

• Loops through each node (A, B, C)

• Prints that node’s routing table

• Shows the cost to directly reach each other node

3. Why the Output Looks Like This

For A:

pgsql

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To B: Cost = 1 To C: Cost = 4

Directly from the dictionary dist['A'].

For B:

pgsql

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To A: Cost = 1 To C: Cost = 2

From dist['B'].

For C:

pgsql

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To A: Cost = 4 To B: Cost = 2

From dist['C'].

4. How This Relates to Distance Vector Routing

• In real distance vector routing, each router shares its table with neighbors and updates costs using the Bellman-Ford algorithm:

new_cost=min⁡(current_cost,cost_to_neighbor+neighbor’s_cost_to_dest)\text{new\_cost} = \min(\text{current\_cost}, \text{cost\_to\_neighbor} + \text{neighbor's\_cost\_to\_dest})new_cost=min(current_cost,cost_to_neighbor+neighbor’s_cost_to_dest)

• Your program is only showing initial direct link costs, not updated values after information exchange.

================ RESTART: C:/Users/giri/Desktop/cnislab/a.py ================
Routing table for A:
To B: Cost = 1
To C: Cost = 4
Routing table for B:
To A: Cost = 1
To C: Cost = 2
Routing table for C:
To A: Cost = 4
To B: Cost = 2
>>> 

Program 7: Data Encryption & Decryption

Video: https://youtu.be/nR1kyLTRHj0

Aim:
To implement basic encryption and decryption (e.g., Caesar cipher).

# Custom substitution cipher

def encrypt(text, mapping):
    result = ''
    for char in text:
        result += mapping.get(char, char)  # Default: keep char if not found
    return result

def decrypt(text, mapping):
    reverse_mapping = {v: k for k, v in mapping.items()}
    result = ''
    for char in text:
        result += reverse_mapping.get(char, char)
    return result


# Example mapping (A-Z mapped to random symbols/numbers)
custom_mapping = {
    'A': '@', 'B': '#', 'C': '9', 'D': '!', 'E': '%',
    'F': '&', 'G': '*', 'H': '1', 'I': '2', 'J': '3',
    'K': '4', 'L': '5', 'M': '6', 'N': '7', 'O': '8',
    'P': '0', 'Q': '?', 'R': '+', 'S': '=', 'T': '~',
    'U': '^', 'V': '$', 'W': '/', 'X': '|', 'Y': '<', 'Z': '>'
}

# Example usage
msg = "HELLO"
cipher = encrypt(msg, custom_mapping)
plain = decrypt(cipher, custom_mapping)

print("Encrypted:", cipher)
print("Decrypted:", plain)

1️⃣ The idea

Instead of shifting letters like in Caesar Cipher (A → D, B → E…),
we assign a completely different symbol, number, or letter to each original letter.
This mapping is fixed and used for both encryption and decryption.

2️⃣ The mapping table

In the code:

python

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custom_mapping = { 'A': '@', 'B': '#', 'C': '9', 'D': '!', 'E': '%', 'F': '&', 'G': '*', 'H': '1', 'I': '2', 'J': '3', 'K': '4', 'L': '5', 'M': '6', 'N': '7', 'O': '8', 'P': '0', 'Q': '?', 'R': '+', 'S': '=', 'T': '~', 'U': '^', 'V': '$', 'W': '/', 'X': '|', 'Y': '<', 'Z': '>' }

• H maps to 1

• E maps to %

• L maps to 5

• O maps to 8

This mapping must be one-to-one — each letter has exactly one unique replacement.

3️⃣ Encryption process

Function:

python

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def encrypt(text, mapping): result = '' for char in text: result += mapping.get(char, char) return result

How it works:

• Reads each character in text

• Looks it up in mapping

• Replaces it with the mapped value

• If it’s not in the mapping (like space or punctuation), it keeps it the same

Example:

perl

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HELLO → 1%5558

(H → 1, E → %, L → 5, O → 8)

4️⃣ Decryption process

Function:

python

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def decrypt(text, mapping): reverse_mapping = {v: k for k, v in mapping.items()} result = '' for char in text: result += reverse_mapping.get(char, char) return result

• First, it reverses the mapping so that @ → A, # → B, 9 → C etc.

• Then, it applies the same replacement logic in reverse

Example:

perl

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1%5558 → HELLO

5️⃣ Advantages over Caesar Cipher

• Caesar Cipher only shifts letters and is easy to crack by frequency analysis

• Substitution Cipher can use symbols, numbers, emojis, and random characters, making it harder to guess

• The mapping can be completely secret and even changed per message

If you want, I can make this automatically generate a random mapping each time so it’s even more secure — like a one-time pad for letters. That would make it much harder to break.

================ RESTART: C:/Users/giri/Desktop/cnislab/a.py ================
Encrypted: 1%558
Decrypted: HELLO

Program 8: Leaky Bucket Algorithm

Aim:
To simulate congestion control using the leaky bucket algorithm.

def leaky_bucket(packet_size, bucket_capacity, output_rate):
    bucket = 0
    for size in packet_size:
        if size + bucket > bucket_capacity:
            print("Packet dropped:", size)
        else:
            bucket += size
            print("Bucket state:", bucket)
            bucket = max(0, bucket - output_rate)

leaky_bucket([4, 2, 6, 3, 5], 10, 3)

1️⃣ Purpose

The Leaky Bucket algorithm is used in networking to control traffic flow — it ensures data is sent at a steady rate, preventing sudden bursts from overloading the network.

• packet_size: Sizes of incoming packets (in arbitrary units)

• bucket_capacity: Max capacity the bucket can hold

• output_rate: How much data is sent (leaked) per cycle

2️⃣ Code Flow

python

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bucket = 0 for size in packet_size:

• We start with an empty bucket (bucket = 0)

• Loop over each incoming packet size

Step-by-step run with input

leaky_bucket([4, 2, 6, 3, 5], 10, 3)

Initial state:
bucket = 0 (empty)

Packet 1: size = 4

• Check: 4 + 0 <= 10 → OK

• Add to bucket: bucket = 0 + 4 = 4

• Output 3 (leak): bucket = 4 - 3 = 1
  ✅ Output → Bucket state: 4

Packet 2: size = 2

• Check: 2 + 1 <= 10 → OK

• Add: bucket = 1 + 2 = 3

• Leak: bucket = 3 - 3 = 0
  ✅ Output → Bucket state: 3

Packet 3: size = 6

• Check: 6 + 0 <= 10 → OK

• Add: bucket = 0 + 6 = 6

• Leak: bucket = 6 - 3 = 3
  ✅ Output → Bucket state: 6

Packet 4: size = 3

• Check: 3 + 3 <= 10 → OK

• Add: bucket = 3 + 3 = 6

• Leak: bucket = 6 - 3 = 3
  ✅ Output → Bucket state: 6

Packet 5: size = 5

• Check: 5 + 3 <= 10 → OK

• Add: bucket = 3 + 5 = 8

• Leak: bucket = 8 - 3 = 5
  ✅ Output → Bucket state: 8

3️⃣ What happens if capacity is exceeded?

If size + bucket > bucket_capacity,
→ The packet is dropped and a message is printed.

Example: If bucket is 9 and a packet of size 4 arrives,
9 + 4 = 13 > 10 → Packet dropped.

4️⃣ Why it’s called “Leaky Bucket”

• Imagine water filling a bucket at different rates (packet arrival)

• Water leaks out at a fixed rate (output_rate)

• If too much water comes in at once, it overflows (packet drop)

================ RESTART: C:/Users/giri/Desktop/cnislab/a.py ================
Bucket state: 4
Bucket state: 3
Bucket state: 6
Bucket state: 6
Bucket state: 8

Program 9: Frame Sorting in Buffer

Aim:
To sort frames received out of order.

def frame_sorting(frames):
    sorted_frames = sorted(frames)
    print("Sorted Frames:", sorted_frames)

frame_sorting([5, 2, 1, 4, 3])

1️⃣ Purpose

This simulates sorting of frames in networking.
In real networks, frames (data packets) might arrive out of order, and before processing, they need to be reordered.

2️⃣ Code Walkthrough

python

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def frame_sorting(frames): sorted_frames = sorted(frames) print("Sorted Frames:", sorted_frames)

• frames → List of frame numbers

• sorted(frames) → Uses Python’s built-in sorting (ascending order by default)

• Prints the sorted order

3️⃣ Execution

Input:

python

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frame_sorting([5, 2, 1, 4, 3])

Step-by-step sorting:

• Start: [5, 2, 1, 4, 3]

• Compare & rearrange → [1, 2, 3, 4, 5]

Output:

less

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Sorted Frames: [1, 2, 3, 4, 5]

4️⃣ Networking Analogy

Imagine you’re receiving video frames:

mathematica

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Frame 5 → Frame 2 → Frame 1 → Frame 4 → Frame 3

If you display them immediately, the video will look jumbled.
Sorting ensures:

mathematica

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Frame 1 → Frame 2 → Frame 3 → Frame 4 → Frame 5

✅ Smooth playback.

================ RESTART: C:/Users/giri/Desktop/cnislab/a.py ================
Sorted Frames: [1, 2, 3, 4, 5]

Program 10: Wireshark Usage

Aim:
To learn basic Wireshark functionalities:

• i. Packet Capture using Wireshark

• ii. Starting Wireshark

• iii. Viewing Captured Traffic

• iv. Using Analysis and Statistics, Filters

💡 Use filters like ip.addr == 192.168.1.1, tcp.port == 80, etc.

Program 11: Nmap Scan

Aim:
To run a basic Nmap scan on a network.

nmap 192.168.1.1
nmap -sP 192.168.1.0/24

Program 12: OS Detection with Nmap

Aim:
To detect Operating Systems of target hosts using Nmap.

nmap -O 192.168.1.1

Program 13: NS2 Simulator Introduction

Aim:
To understand how to simulate networks using NS2.

• Install NS2

• Run .tcl script

• Observe using nam 

# Sample NS2 script
set ns [new Simulator]
set n0 [$ns node]
set n1 [$ns node]
$ns duplex-link $n0 $n1 1Mb 10ms DropTail

 Basics Of Kotlin

https://onecompiler.com/kotlin

Basic Print 

fun main() {
    print("Hello, World!")
    println("Hello, World!")
}

Output:

Hello, World!

Hello, World!

Variables

fun main() {

  val popcorn = 5    // There are 5 boxes of popcorn
  val hotdog = 7     // There are 7 hotdogs
  var customers = 10 // There are 10 customers in the queue
  
  // Some customers leave the queue
  customers = 8
  println(customers)
  // 8  
}

Output:

8

String templates

fun main() {

val customers = 10
println("There are $customers customers ")
// There are 10 customers

println("There are ${customers + 1} customers")
// There are 11 customers
}

Output:

There are 10 customers 
There are 11 customers

Data Types:

String,Double,Boolean

fun main() {
    var name: String = "AEC"
    var year: Int = 2025
    var dv: Double = 2025.25
    var bc: Boolean = true


    println("name ${name}")
    println("year ${year}")
    println("dv ${dv}")
    println("bc ${bc}")
            
}
Output:

name AEC
year 2025
dv 2025.25
bc true

If Statement :

Syntax:

if(condition){

do this

}else{do this}

fun main() {
    var password: String = "1234"
    var givenpassword: String = "1234"
    
    if(givenpassword.equals(password)){
      
      print("Password is Correct")
    }
    else{
      print("Password incorrect")
    }

}

Output:

Password is Correct



fun main() {
    var age:Int=19
    
    if(age>18){
      
      print("Voter id Generated")
    }
    else{
      print("Wait")
    }

}
Output:

Voter id Generated

When Statement same like (C switch)

Syntax:

when(variable){

variableval1->{do this}

variableval2->{do this}

variableval3->{do this}

variableval4->{do this}

variableval5->{do this}

}else{do this}

fun main() {
    val day = 3
    when (day) {
        1 -> {print("Monday") }
        2 -> {print("Tuesday")}
        3 -> {print("Wednesday")}
        else -> {print("Invalid day")}
    }

}

Output:

Wednesday

fun main() {
    val day = 3
    val dayName = when (day) {
        1 -> "Monday"
        2 -> "Tuesday"
        3 -> "Wednesday"
        else -> "Invalid day"
    }
    println(dayName)
}
Output:

Wednesday

in Key Word

fun main() {
    val marks:Int = 60
    when (marks) {
        in 70..100->{print("First Class")}
        in 50..69->{print("Second Class")}        
        else -> {print("Fail")}
    }

}
Output:

Second Class

Loops 

fun main() {
    var i: Int = 1
    while (i <= 5) {
        println("Android Tech")
        i = i + 1
    }
}
Output:

Android Tech
Android Tech
Android Tech
Android Tech
Android Tech

For Loop

fun main() {

  for(item in 1..10){
    println("Loop ${item} $item")
  }
  
}

Output:

Loop 1 1
Loop 2 2
Loop 3 3
Loop 4 4
Loop 5 5
Loop 6 6
Loop 7 7
Loop 8 8
Loop 9 9
Loop 10 10

Break

fun main() {

  for(item in 1..10){
    println("Loop ${item} $item")
    if(item==5){
      break
    }
    
  }
  
}
Output:

Loop 1 1
Loop 2 2
Loop 3 3
Loop 4 4
Loop 5 5

Continue Stmt

fun main() {

  for(item in 1..10){
    
    if(item == 5){
      continue
    }
    println("Loop ${item} $item")
    
  }
  
}
Output:

Loop 1 1
Loop 2 2
Loop 3 3
Loop 4 4
Loop 6 6
Loop 7 7
Loop 8 8
Loop 9 9
Loop 10 10

arrayOf

fun main() {
    val fruits = arrayOf("Apple", "Banana", "Cherry", "Mango")
    //val fruits = arrayOf<String>("Apple", "Banana", "Cherry", "Mango")
    for (fruit in fruits) {
        println(fruit)
    }
}

Output:

Apple
Banana
Cherry
Mango

Array 

fun main() {
    val names = arrayListOf<String>("A", "B", "C", "D")
    println(names.get(2))
    names.add("E")

    for (name in names) {
        println(name)
    }
    //names.remove(element:"C")
    names.remove("C")
    for (name in names) {
        println(name)
    }
  names.removeAll(names)
  println(names)
  
}


Output:

C
A
B
C
D
E
A
B
D
E
[]

Functions Calls

fun main() {
    sample()
    
}

fun sample(){
  println("Hi Hello")
}

Output:
Hi Hello

& 
fun main() {
    sample()
    addition(num1=10,num2=20)
}

fun sample(){
  println("Hi Hello")
}

fun addition(num1:Int,num2:Int){
  println(num1+num2)
  
}
Output:

Hi Hello
30

Ex02

fun main() {
    sample()
    addition(num1=10,num2=20)
    multiplicationTable(number=3)
  
}

fun sample(){
  println("Hi Hello")
}

fun addition(num1:Int,num2:Int){
  println(num1+num2)
  
}
fun multiplicationTable(number:Int){
  var ouput:String?=""
  
  
  for(i in 1..12){
    print("$number X $i = "+(number*i))
    print("\n")
    
  }
  
}

Output:

Hi Hello
30
3 X 1 = 3
3 X 2 = 6
3 X 3 = 9
3 X 4 = 12
3 X 5 = 15
3 X 6 = 18
3 X 7 = 21
3 X 8 = 24
3 X 9 = 27
3 X 10 = 30
3 X 11 = 33
3 X 12 = 36

 xml + kotlin Combination

app\manifests\AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">

    <application
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.MyApplication"
        tools:targetApi="31">
        <activity
            android:name=".MainActivity"
            android:exported="true"
            android:label="@string/app_name"
            android:theme="@style/Theme.MyApplication">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

<!--    <application-->
<!--        android:allowBackup="true"-->
<!--        android:icon="@mipmap/ic_launcher"-->
<!--        android:label="My Application"-->
<!--        android:theme="@style/Theme.MyApplication">-->
<!--        <activity-->
<!--            android:name=".Act1Demo"-->
<!--            android:label="Act1Demo"-->
<!--            android:exported="true">-->
<!--            <intent-filter>-->
<!--                <action android:name="android.intent.action.MAIN" />-->
<!--                <category android:name="android.intent.category.LAUNCHER" />-->
<!--            </intent-filter>-->
<!--        </activity>-->
<!--    </application>-->


</manifest>

app\kotlin+java\MainActivity.kt

package com.example.myapplication

import android.os.Bundle
import android.widget.Toast
import androidx.activity.ComponentActivity
import androidx.activity.compose.setContent
import androidx.activity.enableEdgeToEdge
import androidx.compose.foundation.layout.*
import androidx.compose.material3.*
import androidx.compose.runtime.Composable
import androidx.compose.ui.AbsoluteAlignment
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.tooling.preview.Preview
import androidx.compose.ui.unit.dp
import com.example.myapplication.ui.theme.MyApplicationTheme
import androidx.compose.ui.platform.LocalContext

class MainActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)


        enableEdgeToEdge()
        setContent {
            MyApplicationTheme {
                Scaffold(modifier = Modifier.fillMaxSize()) { innerPadding ->
                    Column(
                        modifier = Modifier
                            .padding(innerPadding)
                            .fillMaxSize()
                            .padding(25.dp),
                        verticalArrangement = Arrangement.Center,
                        horizontalAlignment = Alignment.CenterHorizontally // Centering horizontally
                    ) {
                        Greeting(name = "Android")
                        Spacer(modifier = Modifier.height(16.dp))
                        ShowToastButton()
                        ShowToastButton01()
                    }
                }
            }
        }
    }
}

@Composable
fun Greeting(name: String, modifier: Modifier = Modifier) {
    Text(
        text = "Hello $name!",
        modifier = modifier
    )
}

@Composable
fun ShowToastButton() {
    val context = LocalContext.current
    Button(onClick = {
        Toast.makeText(context, "Button Android clicked!", Toast.LENGTH_SHORT).show()
    }) {
        Text("Show Toast")
    }
}

@Composable
fun ShowToastButton01() {
    val context = LocalContext.current
    Button(onClick = {
        Toast.makeText(context, "Button Java clicked!", Toast.LENGTH_SHORT).show()
    }) {
        Text("Show Toast")
    }
}


@Preview(showBackground = true)
@Composable
fun GreetingPreview() {
    MyApplicationTheme {
        Greeting("Android")
    }
}

Run Application  See Result On ADA

🔍 Key Differences

 19-07-2025 CSE-B(IV)

Basic Android Application Toast Msg Displaying 

app\manifests\AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">

<!--    <application-->
<!--        android:allowBackup="true"-->
<!--        android:dataExtractionRules="@xml/data_extraction_rules"-->
<!--        android:fullBackupContent="@xml/backup_rules"-->
<!--        android:icon="@mipmap/ic_launcher"-->
<!--        android:label="@string/app_name"-->
<!--        android:roundIcon="@mipmap/ic_launcher_round"-->
<!--        android:supportsRtl="true"-->
<!--        android:theme="@style/Theme.MyApplication"-->
<!--        tools:targetApi="31">-->
<!--        <activity-->
<!--            android:name=".MainActivity"-->
<!--            android:exported="true"-->
<!--            android:label="@string/app_name"-->
<!--            android:theme="@style/Theme.MyApplication">-->
<!--            <intent-filter>-->
<!--                <action android:name="android.intent.action.MAIN" />-->

<!--                <category android:name="android.intent.category.LAUNCHER" />-->
<!--            </intent-filter>-->
<!--        </activity>-->
<!--    </application>-->

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="My Application"
        android:theme="@style/Theme.MyApplication">
        <activity
            android:name=".Act1Demo"
            android:label="Act1Demo"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>


</manifest>

app\res\layout\activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

<!--    <Button-->
<!--        android:id="@+id/bt1"-->
<!--        android:text="Android"-->
<!--        android:layout_width="wrap_content"-->
<!--        android:layout_height="wrap_content"-->
<!--        android:onClick="clickAndroid"-->
<!--        android:layout_gravity="center"/>-->

<!--    <Button-->
<!--        android:id="@+id/bt2"-->
<!--        android:text="Java"-->
<!--        android:layout_width="wrap_content"-->
<!--        android:layout_height="wrap_content"-->
<!--        android:onClick="clickJava"-->
<!--        android:layout_gravity="center"/>-->
<!--Old Version-->
    <Button
        android:id="@+id/bt1"
        android:text="Android"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:onClick="clickBtn"
        android:layout_gravity="center"/>

    <Button
        android:id="@+id/bt2"
        android:text="Java"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:onClick="clickBtn"
        android:layout_gravity="center"/>

</LinearLayout>

Output:

xml + java Combination

Create New App

res/layout/activity_main.xml

androidx.constraintlayout.widget.ConstraintLayout

<RelativeLayout

android:background="#009688"

/>

android:layout_width="match_parent" / wrap_content / fill_parent /

100dp(Manual not Recomanded)

android:layout_height="match_parent" / wrap_content / fill_parent(upto android 7 after ) / 100dp (Manual not Recomanded)

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#009688"
    tools:context=".MainActivity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello World!"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</RelativeLayout>

Next add Buttons 

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#009688"
    tools:context=".MainActivity">



Example add 
App/res/layout/activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#009688"
    tools:context=".MainActivity">

<!--    <TextView-->
<!--        android:layout_width="wrap_content"-->
<!--        android:layout_height="wrap_content"-->
<!--        android:text="Hello World! Good Maring how are you When Come to AEC"-->
<!--        app:layout_constraintBottom_toBottomOf="parent"-->
<!--        app:layout_constraintEnd_toEndOf="parent"-->
<!--        app:layout_constraintStart_toStartOf="parent"-->
<!--        app:layout_constraintTop_toTopOf="parent" />-->
<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/bt1"
    android:text="1"
    android:layout_margin="5dp"/>

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/bt2"
        android:text="2"
        android:layout_margin="5dp"
        android:layout_toEndOf="@id/bt1"
        android:layout_toRightOf="@id/bt1"
        />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/bt3"
        android:text="3"
        android:layout_margin="5dp"
        android:layout_toRightOf="@id/bt2"
        />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/bt4"
        android:text="4"
        android:layout_margin="5dp"
        android:layout_below="@id/bt2"
        />

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/bt5"
        android:text="5"
        android:layout_margin="5dp"
        android:layout_below="@id/bt4"
        />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/bt6"
        android:text="6"
        android:layout_below="@id/bt5"
        android:layout_margin="5dp"
        android:layout_alignParentRight="true"
        />


    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/bt7"
        android:text="7"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        />


    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/bt8"
        android:text="8"
        android:layout_alignParentBottom="true"
        />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/bt9"
        android:text="9"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true"
        />


    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/bt10"
        android:text="10"
        android:layout_alignParentBottom="true"
        android:layout_alignParentEnd="true"
        />


</RelativeLayout>

<!--    <TextView-->
<!--        android:layout_width="wrap_content"-->
<!--        android:layout_height="wrap_content"-->
<!--        android:text="Hello World! Good Maring how are you When Come to AEC"-->
<!--        app:layout_constraintBottom_toBottomOf="parent"-->
<!--        app:layout_constraintEnd_toEndOf="parent"-->
<!--        app:layout_constraintStart_toStartOf="parent"-->
<!--        app:layout_constraintTop_toTopOf="parent" />-->
<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/bt1"
    android:text="1"
    android:layout_margin="5dp"/>

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/bt2"
        android:text="2"
        android:layout_margin="5dp"
        android:layout_toEndOf="@id/bt1"
        android:layout_toRightOf="@id/bt1"
        />


</RelativeLayout>

 React Native Side

St01:

1st install Nodejs Software from Website https://nodejs.org/en/download

after Install on OS 

check

PATH = C:\Program Files\nodejs

St02:

Install React Native npm Package 

open cmd

Check node js is installed or not check this command 

C:\Users\giri>node
Welcome to Node.js v18.17.1.
Type ".help" for more information.

Install Packages 

📌 1. Install Prerequisites

✅ Node.js

Install from: https://nodejs.org
Verify:

bash

CopyEdit

node -v npm -v

✅ Android Studio

Install from: https://developer.android.com/studio

During install, check:

• ✅ Android SDK

• ✅ Android SDK Platform

• ✅ Android Virtual Device (AVD)

Then set environment variables:

bash

CopyEdit

setx ANDROID_HOME "C:\Users\<YourUser>\AppData\Local\Android\Sdk" setx PATH "%PATH%;%ANDROID_HOME%\platform-tools"

Restart terminal.

📦 2. Install React Native CLI

bash

CopyEdit

npm install -g react-native-cli

🧱 3. Create New React Native Project

bash

CopyEdit

npx react-native init MyApp cd MyApp

🚀 4. Run the App

Start Metro bundler:

bash

CopyEdit

npx react-native start or

npm start (same way like normal react app)

In a new terminal, run:

bash

CopyEdit

npx react-native run-android

Make sure your Android emulator is running (AVD Manager in Android Studio)
or you’ve connected a real device with USB debugging enabled

Same Way Android Studio  Way02

Hardware requirement : min 8GB Ram and max 8GB<

Install Java  after add Path on system var

PATH = C:\Program Files (x86)\Java\jdk1.7.0_25\bin

JAVA_HOME = C:\Program Files (x86)\Java\jdk1.7.0_25

Android Studio

Install Android Studio 

After 

ANDROID_HOME = C:\Users\giri\AppData\Local\Android\sdk

PATH = %ANDROID_HOME%\platform-tools ; %ANDROID_HOME%\emulator ; %ANDROID_HOME%\tools;%ANDROID_HOME%\tools\bin;%ANDROID_HOME%\cmdline-tools\latest\bin

14-08-2025

Download Java 17 Version 

https://www.oracle.com/java/technologies/javase/jdk17-archive-downloads.html

https://download.oracle.com/java/17/archive/jdk-17.0.12_windows-x64_bin.exe

system Varibles

path = C:\Program Files\Java\jdk-17\bin

%ANDROID_HOME%\tools

%ANDROID_HOME%\platform-tools

%ANDROID_HOME%\emulator

%ANDROID_HOME%\tools\bin

%ANDROID_HOME%\cmdline-tools\latest\bin

C:\Program Files\nodejs\

JAVA_HOME

C:\Program Files\Java\jdk-17

nodejs

C:\Program Files\nodejs

ANDROID_HOME

C:\Users\AECN\AppData\Local\Android\Sdk

Go to Install Path

path location add cmd go to path of project

run react native on android emulator 

See result on  Emulator 

References Many Sources & Add Plugin Your Projects 

✅ Step-by-Step to Build an APK

1. Navigate to the Android folder in your project:

cd android

2. Build the APK (Release mode)

./gradlew assembleRelease

On Windows, use:

gradlew.bat assembleRelease

⏳ This will take a couple of minutes.

If successful, you'll see something like:

BUILD SUCCESSFUL in 1m 20s

3. Find the APK Output

The generated APK will be located here:

<your_project>/android/app/build/outputs/apk/release/app-release.apk

Example:

E:\android\reactnative\app\MyApp\android\app\build\outputs\apk\release\app-release.apk

path of location 

E:\android\reactnative\app\MyApp\android\app\build\outputs\apk\release

You can copy that file to your phone or share it for testing.

E:\android\android apps\LinearLayoutPro\app\src\main\AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">

    <application
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.LinearLayoutPro"
        tools:targetApi="31">
        <activity
            android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

E:\android\android apps\LinearLayoutPro\app\src\main\java\com\example\linearlayoutpro\MainActivity.kt

package com.example.linearlayoutpro

import android.os.Bundle
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity
import androidx.core.view.ViewCompat
import androidx.core.view.WindowInsetsCompat

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        enableEdgeToEdge()
        setContentView(R.layout.activity_main)
        ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main)) { v, insets ->
            val systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars())
            v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom)
            insets
        }
    }
}

E:\android\android apps\LinearLayoutPro\app\src\main\res\layout\activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/main"
    android:orientation="vertical"
    android:background="#0707f1"
    android:weightSum="10">

    <HorizontalScrollView
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="3"
        android:fillViewport="true"
        android:background="#f9f003">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_weight="3"
        android:background="#f9f003"
        android:orientation="horizontal">
        <Button
            android:id="@+id/button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Button"
            android:layout_marginRight="20dp"
            android:layout_weight="1"/>
        <Button
            android:id="@+id/button2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Button"
            android:layout_weight="1"/>
        <Button
            android:id="@+id/button21"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Button"
            android:layout_weight="1"/>

        <Button
            android:id="@+id/button210"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Button"
            android:layout_weight="1"/>

        <Button
            android:id="@+id/button22"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Button"
            android:layout_weight="1"/>

        <Button
            android:id="@+id/button23"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Button"
            android:layout_weight="1"/>

        <Button
            android:id="@+id/button24"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Button"
            android:layout_weight="1"/>


    </LinearLayout>

    </HorizontalScrollView>
    <LinearLayout
        android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_weight="3"
    android:background="#94f50b"
    android:orientation="horizontal">
    <Button
        android:id="@+id/button3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Button"
        android:layout_weight="1"/>
    <Button
        android:id="@+id/button4"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Button"
        android:layout_weight="1"/>
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_weight="2"
    android:background="#33111b"
    android:orientation="horizontal">
    <Button
        android:id="@+id/button5"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Button"
        android:layout_gravity="center"
        android:layout_weight="1"/>
</LinearLayout>
</LinearLayout>

Output:

Android Basic XML TableLayout Example

E:\android\android apps\LinearLayoutPro\app\src\main\AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">

    <application
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.LinearLayoutPro"
        tools:targetApi="31">

        <activity
            android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

E:\android\android apps\LinearLayoutPro\app\src\main\java\com\example\linearlayoutpro\MainActivity.kt

package com.example.linearlayoutpro

import android.os.Bundle
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity
import androidx.core.view.ViewCompat
import androidx.core.view.WindowInsetsCompat

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        enableEdgeToEdge()
        setContentView(R.layout.activity_main)
        ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main)) { v, insets ->
            val systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars())
            v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom)
            insets
        }
    }
}

E:\android\android apps\LinearLayoutPro\app\src\main\res\drawable\border.xml

<?xml version="1.0" encoding="utf-8"?>
<shape
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">
    <stroke android:color="#000"
        android:width="1dp"></stroke>
</shape>

E:\android\android apps\LinearLayoutPro\app\src\main\res\layout\activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/main"
    android:orientation="vertical"
    android:background="#FFEB3B"
    android:weightSum="10">


    <HorizontalScrollView
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="3"
        android:fillViewport="true"
        android:background="#f9f003">

    <TableLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
    <TableRow
        android:layout_width="wrap_content"
        android:layout_height="wrap_content">
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="@drawable/border"
        android:text="S.No"
        android:padding="10dp"/>
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="@drawable/border"
        android:text="Name"
        android:padding="10dp"/>
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="@drawable/border"
        android:text="Mobile"
        android:padding="10dp"/>
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:background="@drawable/border"
            android:text="EMail"
            android:padding="10dp"/>

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:background="@drawable/border"
            android:text="Class"
            android:padding="10dp"/>

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:background="@drawable/border"
            android:text="RollNumber"
            android:padding="10dp"/>

    </TableRow>
    <TableRow
        android:layout_width="wrap_content"
        android:layout_height="wrap_content">
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="1"
        android:padding="10dp"
        android:background="@drawable/border"/>
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Obula Raju D"
        android:padding="10dp"
        android:background="@drawable/border"/>
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="456"
        android:padding="10dp"
        android:background="@drawable/border"/>
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="aa@gmail.com"
        android:padding="10dp"
        android:background="@drawable/border"/>


        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="CSEA"
            android:padding="10dp"
            android:background="@drawable/border"/>

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="524"
            android:padding="10dp"
            android:background="@drawable/border"/>

    </TableRow>
        <TableRow
            android:layout_width="wrap_content"
            android:layout_height="wrap_content">
            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="2"
                android:padding="10dp"
                android:background="@drawable/border"/>
            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="Narayana Raju D"
                android:padding="10dp"
                android:background="@drawable/border"/>
            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="8888"
                android:padding="10dp"
                android:background="@drawable/border"/>
            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="Ebbb@gmail.com"
                android:padding="10dp"
                android:background="@drawable/border"/>

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="CSEB"
                android:padding="10dp"
                android:background="@drawable/border"/>

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="524"
                android:padding="10dp"
                android:background="@drawable/border"/>


        </TableRow>
    </TableLayout>
    </HorizontalScrollView>

</LinearLayout>

Output:

E:\android\android apps\LinearLayoutPro\app\src\main\AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">

    <application
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.LinearLayoutPro"
        tools:targetApi="31">

        <activity
            android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

E:\android\android apps\LinearLayoutPro\app\src\main\java\com\example\linearlayoutpro\MainActivity.kt

package com.example.linearlayoutpro

import android.os.Bundle
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity
import androidx.core.view.ViewCompat
import androidx.core.view.WindowInsetsCompat

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        enableEdgeToEdge()
        setContentView(R.layout.activity_main)
        ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main)) { v, insets ->
            val systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars())
            v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom)
            insets
        }
    }
}

E:\android\android apps\LinearLayoutPro\app\src\main\res\layout\activity_main.xml

<?xml version="1.0" encoding="utf-8"?>

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/main"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:measureAllChildren="true" >

    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        android:background="#FF5722"
        android:weightSum="10">

        <ImageView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:visibility="visible"
        android:src="@drawable/ic_launcher_foreground"/>

    <ImageView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:visibility="visible"
        android:src="@drawable/ic_launcher_background"/>


    </LinearLayout>

</FrameLayout>

Output:

E:\android\android apps\App15\app\src\main\AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">

    <application
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.App15"
        tools:targetApi="31">
        <activity
            android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

E:\android\android apps\App15\app\src\main\res\layout\activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"

    tools:context=".MainActivity">
    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="hello"
        android:textSize="20sp"
        android:textColor="#234098"
        android:textAllCaps="true"
        android:textStyle="bold|italic"
        android:id="@+id/tv"
        android:typeface="monospace"
        android:gravity="center"/>
    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Click Me"
        android:textSize="20sp"
        android:textColor="#234098"
        android:textAllCaps="true"
        android:textStyle="bold|italic"
        android:id="@+id/bt"
        android:typeface="monospace"
        android:gravity="center"/>
</LinearLayout>

E:\android\android apps\App15\app\src\main\java\com\example\app15\MainActivity.kt

package com.example.app15

import android.os.Bundle
import android.view.View
import android.widget.Button
import android.widget.TextView
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity
import androidx.core.view.ViewCompat
import androidx.core.view.WindowInsetsCompat

class MainActivity : AppCompatActivity() {

    var textView: TextView? = null
    var button: Button? = null
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        textView = findViewById<View>(R.id.tv) as TextView
        button = findViewById<View>(R.id.bt) as Button
        button!!.setOnClickListener {
            textView!!.text = "Hi Hello Good morning"
        }
    }
}

Ex02

E:\android\android apps\App15\app\src\main\AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">

    <application
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.App15"
        tools:targetApi="31">
        <activity
            android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

E:\android\android apps\App15\app\src\main\res\layout\activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"

    tools:context=".MainActivity">
    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Hello World!"
        android:textSize="20sp"
        android:textColor="#FF5722"
        android:textAllCaps="true"
        android:textStyle="bold|italic"
        android:id="@+id/tv"
        android:typeface="monospace"
        android:gravity="center"
        />

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Hello World!"
        android:layout_margin="10dp"
        android:padding="10sp"
        android:textSize="20sp"
        android:textColor="#FF5722"
        android:textAllCaps="true"
        android:textStyle="bold|italic"
        android:id="@+id/tv2"
        android:typeface="monospace"
        android:gravity="center"
        />


    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="VISIBLE"
        android:textSize="20sp"
        android:textColor="#234098"
        android:textAllCaps="true"
        android:textStyle="bold|italic"
        android:id="@+id/bt1"
        android:typeface="monospace"
        android:gravity="center"/>

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="INVISIBLE"
        android:textSize="20sp"
        android:textColor="#234098"
        android:textAllCaps="true"
        android:textStyle="bold|italic"
        android:id="@+id/bt2"
        android:typeface="monospace"
        android:gravity="center"/>

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Gone"
        android:textSize="20sp"
        android:textColor="#234098"
        android:textAllCaps="true"
        android:textStyle="bold|italic"
        android:id="@+id/bt3"
        android:typeface="monospace"
        android:gravity="center"/>


</LinearLayout>

E:\android\android apps\App15\app\src\main\java\com\example\app15\MainActivity.kt

package com.example.app15

import android.os.Bundle
import android.view.View
import android.widget.Button
import android.widget.TextView
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity
import androidx.core.view.ViewCompat
import androidx.core.view.WindowInsetsCompat

class MainActivity : AppCompatActivity() {

    //1
    var textView: TextView? = null //here exception means handel null exeption insted of try & catch Blocks
    var button1: Button? = null
    var button2: Button? = null
    var button3: Button? = null


    //String button =new Button() //java every thing is an Object & import from Java side

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        //2
//        textView = findViewById<View>(R.id.tv) as TextView
//        button = findViewById<View>(R.id.bt) as Button
        textView = findViewById(R.id.tv)


        button1 = findViewById(R.id.bt1)
        button2 = findViewById(R.id.bt2)
        button3 = findViewById(R.id.bt3)


        //3
        button1!!.setOnClickListener {
            textView!!.text = "Hi Hello Good morning"
            textView?.visibility=View.VISIBLE
        }

        button2!!.setOnClickListener {
            textView!!.text = "Hi Hello Good morning"
            textView?.visibility=View.INVISIBLE
        }

        button3!!.setOnClickListener {
            textView!!.text = "Hi Hello Good morning"
            textView?.visibility=View.GONE
        }


    }
}

Output:

Using Binding Way To Handel Data

E:\android\android apps\App15\app\build.gradle.kts

    kotlinOptions {
        jvmTarget = "1.8"
    }

    dataBinding{
        enable=true
        //enabled=true old version of android sdk Do it
    }

}

dependencies {

    implementation(libs.androidx.core.ktx)
    implementation(libs.androidx.appcompat)
    implementation(libs.material)
    implementation(libs.androidx.activity)
    implementation(libs.androidx.constraintlayout)
    testImplementation(libs.junit)
    androidTestImplementation(libs.androidx.junit)
    androidTestImplementation(libs.androidx.espresso.core)
}

E:\android\android apps\App15\app\src\main\AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">

    <application
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.App15"
        tools:targetApi="31">
        <activity
            android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

E:\android\android apps\App15\app\src\main\res\layout\activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<layout>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"

    tools:context=".MainActivity">
    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Hello World!"
        android:textSize="20sp"
        android:textColor="#FF5722"
        android:textAllCaps="true"
        android:textStyle="bold|italic"
        android:id="@+id/tv"
        android:typeface="monospace"
        android:gravity="center"
        />

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Hello World!"
        android:layout_margin="10dp"
        android:padding="10sp"
        android:textSize="20sp"
        android:textColor="#FF5722"
        android:textAllCaps="true"
        android:textStyle="bold|italic"
        android:id="@+id/tv2"
        android:typeface="monospace"
        android:gravity="center"
        />


    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="VISIBLE"
        android:textSize="20sp"
        android:textColor="#234098"
        android:textAllCaps="true"
        android:textStyle="bold|italic"
        android:id="@+id/bt1"
        android:typeface="monospace"
        android:gravity="center"/>

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="INVISIBLE"
        android:textSize="20sp"
        android:textColor="#234098"
        android:textAllCaps="true"
        android:textStyle="bold|italic"
        android:id="@+id/bt2"
        android:typeface="monospace"
        android:gravity="center"/>

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Gone"
        android:textSize="20sp"
        android:textColor="#234098"
        android:textAllCaps="true"
        android:textStyle="bold|italic"
        android:id="@+id/bt3"
        android:typeface="monospace"
        android:gravity="center"/>

</LinearLayout>
</layout>

E:\android\android apps\App15\app\src\main\java\com\example\app15\MainActivity.kt

package com.example.app15

import android.os.Bundle
import android.view.View
import android.widget.Button
import android.widget.TextView
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity
import androidx.core.view.ViewCompat
import androidx.core.view.WindowInsetsCompat
import androidx.databinding.DataBindingUtil
import com.example.app15.databinding.ActivityMainBinding

class MainActivity : AppCompatActivity() {

    //1
    //var textView: TextView? = null //here exception means handel null exeption insted of try & catch Blocks
    //var button1: Button? = null
    //var button2: Button? = null
    //var button3: Button? = null

    var binding:ActivityMainBinding?=null



    //String button =new Button() //java every thing is an Object & import from Java side

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        //setContentView(R.layout.activity_main)


            binding=DataBindingUtil.setContentView(this,R.layout.activity_main)

        //2
//        textView = findViewById<View>(R.id.tv) as TextView
//        button = findViewById<View>(R.id.bt) as Button

        //textView = findViewById(R.id.tv)


        //button1 = findViewById(R.id.bt1)
        //button2 = findViewById(R.id.bt2)
        //button3 = findViewById(R.id.bt3)


        //3
        /*
        button1!!.setOnClickListener {
            textView!!.text = "Hi Hello Good morning"
            textView?.visibility=View.VISIBLE
        }

        button2!!.setOnClickListener {
            textView!!.text = "Hi Hello Good morning"
            textView?.visibility=View.INVISIBLE
        }

        button3!!.setOnClickListener {
            textView!!.text = "Hi Hello Good morning"
            textView?.visibility=View.GONE
        }
        */

        binding?.bt1!!.setOnClickListener {
            binding?.tv2?.text = "Hi Hello Good morning"
            binding?.tv2?.visibility=View.VISIBLE
        }

        binding?.bt2!!.setOnClickListener {
            binding?.tv2?.text = "Hi Hello Good morning"
            binding?.tv2?.visibility=View.INVISIBLE
        }

        binding?.bt3!!.setOnClickListener {
            binding?.tv2?.text = "Hi Hello Good morning"
            binding?.tv2?.visibility=View.GONE
        }


    }
}

reference Link Code : https://androindian.com/registration-using-retrofit-raw-data/

Do CURD Operation Using API Via Android sdk show Data from Server Send Points 

Do POST Operation 

build.gradle

E:\android\android apps\APIIntegration\app\src\main\AndroidManifest.xml

    dataBinding{
        enable=true
    }

dependencies {
...................

implementation ("com.squareup.retrofit2:converter-gson:2.4.0")
implementation ("com.squareup.retrofit2:retrofit:2.4.0")
implementation ("com.google.code.gson:gson:2.8.9")
}

E:\android\android apps\APIIntegration\app\src\main\AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">

    <uses-permission android:name="android.permission.INTERNET"/>

    <application
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.APIIntegration"
        tools:targetApi="31">
        <activity
            android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

E:\android\android apps\APIIntegration\app\src\main\res\layout\activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<layout>
    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".MainActivity"
        android:id="@+id/main"
        android:orientation="vertical">

        <androidx.cardview.widget.CardView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_margin="5dp"
            android:layout_centerHorizontal="true"
            android:layout_centerVertical="true">

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_margin="5dp"
                android:orientation="vertical">

                <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="Register here"
                    />

                <com.google.android.material.textfield.TextInputLayout
                    android:id="@+id/username"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:hint="UserName"
                    android:layout_margin="5dp">

                    <com.google.android.material.textfield.TextInputEditText
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"
                        />

                </com.google.android.material.textfield.TextInputLayout>

<!--                <com.google.android.material.textfield.TextInputLayout-->
<!--                    android:id="@+id/email"-->
<!--                    android:layout_width="match_parent"-->
<!--                    android:layout_height="wrap_content"-->
<!--                    android:hint="Email"-->
<!--                    android:layout_margin="5dp">-->

<!--                    <com.google.android.material.textfield.TextInputEditText-->
<!--                        android:layout_width="match_parent"-->
<!--                        android:layout_height="wrap_content"-->
<!--                        />-->

<!--                </com.google.android.material.textfield.TextInputLayout>-->

                <com.google.android.material.textfield.TextInputLayout
                    android:id="@+id/passwod"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:hint="Password"
                    android:layout_margin="5dp">

                    <com.google.android.material.textfield.TextInputEditText
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"
                        />

                </com.google.android.material.textfield.TextInputLayout>

                <Button
                    android:id="@+id/register"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="Register"
                    android:layout_gravity="center"
                    />
            </LinearLayout>
        </androidx.cardview.widget.CardView>

    </RelativeLayout>
</layout>

E:\android\android apps\APIIntegration\app\src\main\java\com\example\apiintegration\MainActivity.kt

package com.example.apiintegration
import android.content.Intent
import android.os.Bundle
import android.widget.Toast
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity
import androidx.core.view.ViewCompat
import androidx.core.view.WindowInsetsCompat
import androidx.databinding.DataBindingUtil
import com.example.apiintegration.databinding.ActivityMainBinding
import com.google.gson.JsonParser
import org.json.JSONObject
import retrofit2.Call
import retrofit2.Callback
import retrofit2.Retrofit
import retrofit2.converter.gson.GsonConverterFactory
import retrofit2.Response
import android.util.Log

class MainActivity : AppCompatActivity() {

    var binding: ActivityMainBinding?=null
    val TAG = "MainActivity"
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding= DataBindingUtil.setContentView(this,R.layout.activity_main)



        binding?.register?.setOnClickListener{
            var name=binding?.username?.editText?.text.toString().trim()
//            var email=binding?.email?.editText?.text.toString().trim()
            var password=binding?.passwod?.editText?.text.toString().trim()

            var jsonObject= JSONObject()
            // jsonObject.put("key is from api","valuee from xml")
            jsonObject.put("username",name)
            jsonObject.put("password",password)
//            jsonObject.put("email",email)

            var retrofit= Retrofit.Builder().
            baseUrl("endpoint/api/")
                .addConverterFactory(GsonConverterFactory.create()).build()

            var retroInterface=retrofit.create(SampleProjectInterface::class.java)

            var regisetercall: Call<RegisterResponse>

            val `xyz` = JsonParser().parse(jsonObject.toString()).asJsonObject

            Log.d(TAG, "Request JSON: $xyz")

            //8
            val regResponseCall = retroInterface.createUser(`xyz`)

            regResponseCall?.enqueue(object : Callback<RegisterResponse?>{
                override fun onResponse(
                    call: Call<RegisterResponse?>,
                    response: Response<RegisterResponse?>

                ) {
                    Log.d(TAG, "Response received: $response,$call")
                    if (response.isSuccessful && response.body() != null) {
                        val registeredUsername = response.body()?.username
                        Toast.makeText(this@MainActivity, "Registered: $registeredUsername", Toast.LENGTH_LONG).show()

                      // Navigate to Login activity or next step if needed
                     // startActivity(Intent(this@MainActivity, LoginActivity::class.java))
                    } else {
                        Toast.makeText(this@MainActivity, "Registration failed: ${response.errorBody()?.string()}", Toast.LENGTH_LONG).show()
                    }

                //                    Toast.makeText(this@MainActivity,""+response.body(),Toast.LENGTH_LONG).show()
//                    var res=response.body()?.status
//                    if(res.equals("failed")){
//                        var res1=response.body()?.key
//                        Toast.makeText(this@MainActivity,""+res1,Toast.LENGTH_LONG).show()
//
//                    }else{
//                        var res1=response.body()?.key
//                        Toast.makeText(this@MainActivity,""+res1,Toast.LENGTH_LONG).show()
//                        var intent= Intent(this@MainActivity, Login::class.java)
//                        startActivity(intent)
//                    }
                }

                override fun onFailure(call: Call<RegisterResponse?>, t: Throwable) {
                    Log.d(TAG, "OnFailure: $call,$t")
                    Toast.makeText(this@MainActivity,""+t.toString(),Toast.LENGTH_LONG).show()
                }
            })

//        enableEdgeToEdge()
//        setContentView(R.layout.activity_main)
//        ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main)) { v, insets ->
//            val systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars())
//            v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom)
//            insets
//        }
    }

    }
}

E:\android\android apps\APIIntegration\app\src\main\java\com\example\apiintegration\SampleProjectInterface.kt

package com.example.apiintegration

import com.google.gson.JsonObject
import retrofit2.Call
import retrofit2.http.Body
import retrofit2.http.GET
import retrofit2.http.Headers
import retrofit2.http.POST

public interface SampleProjectInterface {


    @Headers("Content-Type: application/json")
    @POST("register/")
    fun createUser(@Body jsonObject: JsonObject): Call<RegisterResponse>?


}

E:\android\android apps\APIIntegration\app\src\main\java\com\example\apiintegration\RegisterResponse.kt

package com.example.apiintegration

//https://www.jsonschema2pojo.org/  1st do it here json in website to do convert java to kt next 
//✅ 1. Ensure You're Using the Right Shortcut
//For Windows/Linux:
//Ctrl + Alt + Shift + K


import com.google.gson.annotations.Expose
import com.google.gson.annotations.SerializedName


class RegisterResponse {
    @SerializedName("username")
    @Expose
    var username: String? = null
}

 CSE - III (A) 21/07/2025 & CSE - III(B) not

EX 3.Find All the IP Addresses on your network,Unicast,Multicast,and Broadcast on your network.

Video Link : https://youtu.be/AVUZpTW_uhE

Install Cisco Packet Tracer software Testing Network Setup

Note:1.Small Switch connect to Devices Via Wire and Other case Wifi(802.11a to f)

🧾 IPv4 vs IPv6 Comparison Table

Here's a clear summary of IPv4 classification, including Class A, B, C, their ranges, default subnet masks, host calculations, and example IPs.

📘 IPv4 Address Classes

🧮 Quick Calculations:

• Hosts per Network = 2^{host bits} – 2
  (Subtract 2 for network and broadcast addresses)

Example for Class C:

• 8 host bits → 2⁸ – 2 = 254 hosts

Example for Class A:

• 24 host bits → 2²⁴ – 2 = 16,777,214 hosts

✅ Special Notes:

• 127.x.x.x is reserved for loopback (localhost).

• 169.254.x.x is for APIPA (Automatic Private IP Addressing).

• Common Private IP ranges:

  • Class A: 10.0.0.0 – 10.255.255.255

  • Class B: 172.16.0.0 – 172.31.255.255

  • Class C: 192.168.0.0 – 192.168.255.255

Let me know if you want the IPv6 version or CIDR notation summary next.

🧾 Updated Table: Unicast vs Broadcast vs Multicast
 

Basic Switch to Node(Client or Server os or IOT Devices & Android OS Phones  & Any IP Devices )

Switch>enable
Switch#configure terminal
Switch(config)#hostname HYD-SW01
HYD-SW01(config)#
HYD-SW01#end

To verify The Current Configuration
syntax:
show vlan

HYD-SW01#show vlan

VLAN Name                             Status    Ports
---- -------------------------------- --------- -------------------------------
1    default                          active    Fa0/1, Fa0/2, Fa0/3, Fa0/4
                                                Fa0/5, Fa0/6, Fa0/7, Fa0/8
                                                Fa0/9, Fa0/10, Fa0/11, Fa0/12
                                                Fa0/13, Fa0/14, Fa0/15, Fa0/16
                                                Fa0/17, Fa0/18, Fa0/19, Fa0/20
                                                Fa0/21, Fa0/22, Fa0/23, Fa0/24
1002 fddi-default                     act/unsup 
1003 token-ring-default               act/unsup 
1004 fddinet-default                  act/unsup 
1005 trnet-default                    act/unsup 

VLAN Type  SAID       MTU   Parent RingNo BridgeNo Stp  BrdgMode Trans1 Trans2
---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------
1    enet  100001     1500  -      -      -        -    -        0      0
1002 fddi  101002     1500  -      -      -        -    -        0      0   
1003 tr    101003     1500  -      -      -        -    -        0      0   
1004 fdnet 101004     1500  -      -      -        ieee -        0      0   
1005 trnet 101005     1500  -      -      -        ibm  -        0      0   

Remote SPAN VLANs
------------------------------------------------------------------------------


Primary Secondary Type              Ports
------- --------- ----------------- ------------------------------------------
HYD-SW01#

syntax:
show mac-address-table 

HYD-SW01#show mac-address-table 
          Mac Address Table
-------------------------------------------

Vlan    Mac Address       Type        Ports
----    -----------       --------    -----

syntax:
show ip interface brief 


HYD-SW01#show ip interface brief 
Interface              IP-Address      OK? Method Status                Protocol
 
FastEthernet0/1        unassigned      YES manual up                    up
 
FastEthernet0/2        unassigned      YES manual up                    up
 
FastEthernet0/3        unassigned      YES manual up                    up
 
FastEthernet0/4        unassigned      YES manual up                    up
 
FastEthernet0/5        unassigned      YES manual up                    up
 
FastEthernet0/6        unassigned      YES manual up                    up
 
FastEthernet0/7        unassigned      YES manual up                    up
 
FastEthernet0/8        unassigned      YES manual up                    up
 
FastEthernet0/9        unassigned      YES manual down                  down
 
FastEthernet0/10       unassigned      YES manual down                  down
 
FastEthernet0/11       unassigned      YES manual down                  down
 
FastEthernet0/12       unassigned      YES manual down                  down
 
FastEthernet0/13       unassigned      YES manual down                  down
 
FastEthernet0/14       unassigned      YES manual down                  down
 
FastEthernet0/15       unassigned      YES manual down                  down
 
FastEthernet0/16       unassigned      YES manual down                  down
 
FastEthernet0/17       unassigned      YES manual down                  down
 
FastEthernet0/18       unassigned      YES manual down                  down
 
FastEthernet0/19       unassigned      YES manual down                  down
 
FastEthernet0/20       unassigned      YES manual down                  down
 
FastEthernet0/21       unassigned      YES manual down                  down
 
FastEthernet0/22       unassigned      YES manual down                  down
 
FastEthernet0/23       unassigned      YES manual down                  down
 
FastEthernet0/24       unassigned      YES manual down                  down
 
Vlan1                  unassigned      YES manual administratively down down


HYD-SW01#show interface fa0/1
FastEthernet0/1 is up, line protocol is up (connected)
  Hardware is Lance, address is 00d0.d341.b701 (bia 00d0.d341.b701)
 BW 100000 Kbit, DLY 1000 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Full-duplex, 100Mb/s
  input flow-control is off, output flow-control is off
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:08, output 00:00:05, output hang never
  Last clearing of "show interface" counters never
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue :0/40 (size/max)
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec
     956 packets input, 193351 bytes, 0 no buffer
     Received 956 broadcasts, 0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
     0 watchdog, 0 multicast, 0 pause input
     0 input packets with dribble condition detected
     2357 packets output, 263570 bytes, 0 underruns
     0 output errors, 0 collisions, 10 interface resets
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier
     0 output buffer failures, 0 output buffers swapped out


HYD-SW01#show vlan

VLAN Name                             Status    Ports
---- -------------------------------- --------- -------------------------------
1    default                          active    Fa0/1, Fa0/2, Fa0/3, Fa0/4
                                                Fa0/5, Fa0/6, Fa0/7, Fa0/8
                                                Fa0/9, Fa0/10, Fa0/11, Fa0/12
                                                Fa0/13, Fa0/14, Fa0/15, Fa0/16
                                                Fa0/17, Fa0/18, Fa0/19, Fa0/20
                                                Fa0/21, Fa0/22, Fa0/23, Fa0/24
1002 fddi-default                     act/unsup 
1003 token-ring-default               act/unsup 
1004 fddinet-default                  act/unsup 
1005 trnet-default                    act/unsup 

VLAN Type  SAID       MTU   Parent RingNo BridgeNo Stp  BrdgMode Trans1 Trans2
---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------
1    enet  100001     1500  -      -      -        -    -        0      0
1002 fddi  101002     1500  -      -      -        -    -        0      0   
1003 tr    101003     1500  -      -      -        -    -        0      0   
1004 fdnet 101004     1500  -      -      -        ieee -        0      0   
1005 trnet 101005     1500  -      -      -        ibm  -        0      0   

Remote SPAN VLANs
------------------------------------------------------------------------------


Primary Secondary Type              Ports
------- --------- ----------------- ------------------------------------------


HYD-SW01#configure terminal

VLAN Creation:

HYD-SW01(config)#
HYD-SW01(config)#vlan 10
HYD-SW01(config-vlan)#name CSE
HYD-SW01(config-vlan)#exit
HYD-SW01(config)#vlan 20
HYD-SW01(config-vlan)#name ECE
HYD-SW01(config-vlan)#exit

Assigning membership to ports:

HYD-SW01(config)#interface fastEthernet 0/2
HYD-SW01(config-if)#switchport mode access
HYD-SW01(config-if)#switchport access vlan 10
HYD-SW01(config-if)#exit
HYD-SW01(config)#interface fastEthernet 0/4
HYD-SW01(config-if)#switchport mode access 
HYD-SW01(config-if)#switchport access vlan 20

HYD-SW01(config-if)#exit
HYD-SW01(config)#exit
HYD-SW01#

verification of vlan

HYD-SW01#show vlan 

VLAN Name                             Status    Ports
---- -------------------------------- --------- -------------------------------
1    default                          active    Fa0/1, Fa0/3, Fa0/5, Fa0/6
                                                Fa0/7, Fa0/8, Fa0/9, Fa0/10
                                                Fa0/11, Fa0/12, Fa0/13, Fa0/14
                                                Fa0/15, Fa0/16, Fa0/17, Fa0/18
                                                Fa0/19, Fa0/20, Fa0/21, Fa0/22
                                                Fa0/23, Fa0/24
10   CSE                              active    Fa0/2
20   ECE                              active    Fa0/4
1002 fddi-default                     act/unsup 
1003 token-ring-default               act/unsup 
1004 fddinet-default                  act/unsup 
1005 trnet-default                    act/unsup 

VLAN Type  SAID       MTU   Parent RingNo BridgeNo Stp  BrdgMode Trans1 Trans2
---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------
1    enet  100001     1500  -      -      -        -    -        0      0
10   enet  100010     1500  -      -      -        -    -        0      0
20   enet  100020     1500  -      -      -        -    -        0      0
1002 fddi  101002     1500  -      -      -        -    -        0      0   
1003 tr    101003     1500  -      -      -        -    -        0      0   
1004 fdnet 101004     1500  -      -      -        ieee -        0      0   
1005 trnet 101005     1500  -      -      -        ibm  -        0      0   

Remote SPAN VLANs
------------------------------------------------------------------------------


Primary Secondary Type              Ports
------- --------- ----------------- ------------------------------------------

Report 3rd Year CSE-B

Before to Now 06-08-2025

23HN1A0579
23HN1A0556
23HN1A0583(06-08-2025)

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23HN1A0576

23HN1A0559

23HN1A0562(14-08-2025) - 2copys

23HN1A0563(07/08/2025)

No submited Documents Date of Observation (08-06-2025)

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23R61A0524

23HN1A0585
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EX4&EX5

📦 Routing & Routing Table

Video Reference : https://youtu.be/T1B3E06YP40

What is Routing?

Routing is the process of selecting the best path in a network to forward data packets from source to destination.

What is a Routing Table?

A routing table stores routes (paths) to different network destinations. Each entry usually includes:

• Destination Network

• Subnet Mask

• Next Hop / Gateway

• Interface

• Metric (Cost)

🔁 1. Static Routing

• Manually configured by the network administrator.

• Does not change unless manually updated.

• Best for small, stable networks.

bash

✅ Network Design

arduino

CopyEdit

Laptop0 --- Switch0 --- Router3 --- Serial --- Router4 --- Switch1 --- Laptop1

Routers add Module Physical ->WIC-2T switch of Power on Router Then Do it

🧱 Devices Needed (Add These in Packet Tracer)

🔌 Module You Need to Add to Routers

On each 1941 Router, add:

• Serial Interface module:
  HWIC-2T (drag it into the empty WIC slot in the back)

⚠️ Turn the router OFF before inserting the module in Packet Tracer, then turn it back ON.

🧠 IP Addressing Plan

🖥️ Laptop Configuration

Laptop0:

• IP: 192.168.1.10

• Subnet Mask: 255.255.255.0

• Gateway: 192.168.1.1

Laptop1:

• IP: 192.168.2.10

• Subnet Mask: 255.255.255.0

• Gateway: 192.168.2.1

Configure under Desktop > IP Configuration

📡 Router3 Configuration

bash

CopyEdit

enable 
conf t 
hostname Router3 
interface GigabitEthernet0/0 
ip address 192.168.1.1 255.255.255.0 
no shutdown 
interface Serial0/0/0 
ip address 10.0.0.1 255.255.255.252 
clock rate 64000 
no shutdown 
ip route 192.168.2.0 255.255.255.0 10.0.0.2 
end 
wr

📡 Router4 Configuration

bash

CopyEdit

enable 
conf t 
hostname Router4 
interface GigabitEthernet0/0 
ip address 192.168.2.1 255.255.255.0 
no shutdown 
interface Serial0/0/0 
ip address 10.0.0.2 255.255.255.252 
no shutdown 
ip route 192.168.1.0 255.255.255.0 10.0.0.1 
end 
wr

🧪 Test Commands

After configuration, test:

1. From Laptop0:

   bash

   CopyEdit

   ping 192.168.1.1 ! Router3 ping 192.168.2.1 ! Router4 ping 192.168.2.10 ! Laptop1

2. From Router3:

   bash

   CopyEdit

   ping 10.0.0.2 ! Router4 serial

✅ Done! You should now have a fully working 2-router network.

Let me know if you'd like the .pkt file or want to expand this design to include dynamic routing or VLANs.

🔄 2. Dynamic Routing

• Automatically updates routes based on network changes.

• Uses routing protocols to exchange route information.

🌐 Classification of Routing Protocols

📍 IGP (Interior Gateway Protocol)

Used within a single organization or autonomous system (AS).

Types:

🚀 EGP (Exterior Gateway Protocol)

Used between different organizations (between ASes).

• BGP (Border Gateway Protocol) is the only widely used EGP.

• BGP is path vector-based, and used on the internet for inter-AS routing.

bash

CopyEdit

# BGP Example: router bgp 65001 neighbor 192.168.1.1 remote-as 65002

⚙️ Summary Table

CSE-B Completed And Subimited 

23HN1A0574(07-08-2025)

23HN1A0576

22HN1A0559

23HN1A0572(18/07/2025)

23HN1A0562(14-08-2025)

23HN1A0563(14/08/2025)

Code:

Video Link : https://youtu.be/ju04tW0wUiY

📘 Title: "From Records to Response: A Frontend Story of API Data Flow"

🔹 Step 1: The Origin – Database Records

Imagine a college maintains digital student records — like subject details, results, or personal info — inside a system (a database). These records sit quietly, waiting to be used.

🔹 Step 2: Serialization – Making Data Understandable

Before this data can be shared, it needs to be converted into a universal format like JSON. This format is readable by all — websites, mobile apps, or other software.

Think of this like converting handwritten notes into a typed document anyone can read.

🔹 Step 3: API Endpoint – The Doorway

An API endpoint acts like a door. When a browser or app knocks (makes a request), it opens up and provides the serialized data in response.

URL Example: https://example.com/api/results/

🔹 Step 4: AJAX Call – The Frontend Makes a Request

On a webpage, JavaScript (via AJAX) sends a network call to this endpoint. This is like placing an order:

🔹 Step 4: AJAX Call – The Frontend Makes a Request

On a webpage, JavaScript (via AJAX) sends a network call to this endpoint. This is like placing an order:

javascript

CopyEdit

$.ajax({ url: "/api/results/", method: "GET", success: function(data) { // use the structured response console.log(data); } });

🔹 Step 5: The Response – Structured Data Arrives

The AJAX call receives a JSON response with all the needed details. Example:

json

CopyEdit

[ { "id": 1, "student": "John Doe", "subject_id": 101, "subject_name": "Computer Networks", "subject_code": "23A05501T", "marks": 87 }, ... ]

🔹 Step 6: Data for Any Application

This structured data can now be:

• Rendered in an HTML table

• Visualized in charts

• Sent to another frontend app (like React or Android)

• Exported to Excel/PDF

• Used in reports

✅ Conclusion:

Even without touching the backend, the journey of data from a database to your HTML page involves:

1. Serializing it into JSON

2. Serving it through an endpoint

3. Accessing it via AJAX

4. Displaying or forwarding it to other apps

This is how raw data becomes usable, visible, and powerful.

Would you like a visual diagram or simple code setup with table display for this too?

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Student Result Search</title>
  <script src="https://code.jquery.com/jquery-3.6.0.min.js"></script>

  <style>
    #autocomplete_suggestions {
      border: 1px solid #ccc;
      max-height: 150px;
      overflow-y: auto;
      position: absolute;
      background: white;
      width: 220px;
      z-index: 999;
    }
    .suggestion-item {
      padding: 8px;
      cursor: pointer;
    }
    .suggestion-item:hover {
      background-color: #f0f0f0;
    }
    table {
      margin-top: 20px;
      border-collapse: collapse;
      width: 100%;
    }
    th, td {
      padding: 8px;
      border: 1px solid #ccc;
    }
    th {
      background-color: #eee;
    }
  </style>
</head>
<body>

  <h2>Search Student by Hallticket Number</h2>
  <input type="text" id="roll_number_input" placeholder="Enter Roll Number" autocomplete="off" style="width: 220px;" />
  <div id="autocomplete_suggestions"></div>

  <table id="result_table">
    <thead>
      <tr>
        <th>Year</th>
        <th>Semester</th>
        <th>Subject Name</th>
        <th>Subject Code</th>
        <th>Credits</th>
        <th>Grade</th>
        <th>Status</th>
      </tr>
    </thead>
    <tbody>
      <!-- Results will appear here -->
    </tbody>
  </table>

  <script>
    // Autocomplete for roll number
    $('#roll_number_input').on('input', function () {
      let query = $(this).val().toLowerCase();
      if (query.length < 3) {
        $('#autocomplete_suggestions').empty();
        return;
      }

      $.get('https://aec.sites.marrichet.com/api/student/', function (data) {
        let filtered = data.filter(item => item.roll_number.toLowerCase().includes(query));
        let suggestions = filtered.map(item => 
          `<div class="suggestion-item" data-id="${item.id}" data-roll="${item.roll_number}">
            ${item.roll_number} (${item.studentclassname})
          </div>`
        ).join('');
        $('#autocomplete_suggestions').html(suggestions);
      });
    });

    // On click suggestion
    $(document).on('click', '.suggestion-item', function () {
      let studentId = $(this).data('id');
      let roll = $(this).data('roll');

      $('#roll_number_input').val(roll);
      $('#autocomplete_suggestions').empty();

      $.get(`https://aec.sites.marrichet.com/api/result/?student__id=${studentId}`, function (results) {
        let rows = results.map(r => `
          <tr>
            <td>${r.year}</td>
            <td>${r.semester}</td>
            <td>${r.subject_name || ''}</td>
            <td>${r.subject_code || ''}</td>
            <td>${r.credits != null ? r.credits : ''}</td>
            <td>${r.grade || ''}</td>
            <td>${r.pass_status || ''}</td>
          </tr>
        `).join('');

        if (rows.length > 0) {
          $('#result_table tbody').html(rows);
        } else {
          $('#result_table tbody').html('<tr><td colspan="7">No results found.</td></tr>');
        }
      });
    });
  </script>

</body>
</html>
 

3rd Year CSE-B

completed  

23HN1A0562(14-08-2025)

23HN1A0563(14/08/2025)

23HN1A0572(14/08/2025) 

 CSE - III (A)14/07/2025  & CSE - III(B) 16/07/2025

EX 2.Work with the commands Ping,Tracert,Ipconfig,pathping,telnet,ftp,getmac,ARP,Hostname,Nbstat,netdiag,and Nslookup

ping Tests reachability of a host. <br>

ping google.com
ping 8.8.8.8 

tracert Traces route packets take to a host. <br>

tracert google.com #dns
tracert 8.8.8.8  #IP

ipconfig Shows IP configuration. <br>

ipconfig /all

pathping Combines ping + tracert for detailed path info. <br>

pathping google.com

telnet Tests remote port connectivity. <br> telnet towel.blinkenlights.nl (ASCII Star Wars)

telnet towel.blinkenlights.nl # DNS
telnet 192.168.1.1 #IP

ftp Access FTP server. <br>

ftp ftp.gnu.org #DNS
ftp 192.168.1.1 #ip

getmac Displays MAC address. <br>

 getmac

arp Shows IP-to-MAC address mapping. <br>

 arp -a

hostname Displays the PC name. <br>

hostname

nbtstat Shows NetBIOS info. <br>

nbtstat -n

netdiag Diagnoses network issues (deprecated; install manually on modern Windows).

nslookup Queries DNS servers. <br>

nslookup www.google.com

google.com

Report 3rd Year CSE-B(2025-07-21 to 06-08-2025)

completed

23HN1A0582
23HN1A0581
23HN1A0580
23HN1A0579
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No submited Documents Date of Observation (08-06-2025)

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3rd Year CSE-A(2025-07-21 to 06-08-2025)

-----------------------

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Code 

<!DOCTYPE html>
<html>
<head>
  <title>GeoAPI Interaction (Google Tiles)</title>
  <meta charset="utf-8" />
  <meta name="viewport" content="width=device-width, initial-scale=1.0">

  <!-- Leaflet CSS -->
  <link rel="stylesheet" href="https://unpkg.com/leaflet/dist/leaflet.css"/>
  <!-- Marker Cluster CSS -->
  <link rel="stylesheet" href="https://unpkg.com/leaflet.markercluster/dist/MarkerCluster.css" />
  <link rel="stylesheet" href="https://unpkg.com/leaflet.markercluster/dist/MarkerCluster.Default.css" />

  <style>
    #map { height: 600px; }
  </style>
</head>
<body>
  <h2>GEOAPI Intraction</h2>
  <div id="map"></div>

  <!-- Leaflet JS -->
  <script src="https://unpkg.com/leaflet/dist/leaflet.js"></script>
  <script src="https://unpkg.com/leaflet.markercluster/dist/leaflet.markercluster.js"></script>

  <script>
    // Initialize map
    var map = L.map('map').setView([14.62, 79.42], 9);

    // ✅ Google Maps tile layer
    var googleStreets = L.tileLayer('http://{s}.google.com/vt/lyrs=m&x={x}&y={y}&z={z}', {
        maxZoom: 20,
        subdomains:['mt0','mt1','mt2','mt3']
    }).addTo(map);

    // Other Google layers (optional)
    var googleHybrid = L.tileLayer('http://{s}.google.com/vt/lyrs=y&x={x}&y={y}&z={z}', {
        maxZoom: 20,
        subdomains:['mt0','mt1','mt2','mt3']
    });
    var googleSat = L.tileLayer('http://{s}.google.com/vt/lyrs=s&x={x}&y={y}&z={z}', {
        maxZoom: 20,
        subdomains:['mt0','mt1','mt2','mt3']
    });

    // Cluster group
    var markers = L.markerClusterGroup();

    // Fetch GeoJSON from API
    fetch("https://aec.sites.marrichet.com/api/studentlocation/")
      .then(response => response.json())
      .then(data => {
        var geojsonLayer = L.geoJSON(data, {
          onEachFeature: function (feature, layer) {
            layer.bindPopup(
              `<b>Student ID:</b> ${feature.id}<br>
               <b>Coordinates:</b> ${feature.geometry.coordinates[1]}, ${feature.geometry.coordinates[0]}`
            );
          }
        });

        markers.addLayer(geojsonLayer);
        map.addLayer(markers);
        map.fitBounds(markers.getBounds());
      });

    // ✅ Layer control for switching Google maps
    L.control.layers({
      "Google Streets": googleStreets,
      "Google Satellite": googleSat,
      "Google Hybrid": googleHybrid
    }).addTo(map);

  </script>
</body>
</html>

Output:

Scikit Image:

Uploading and Viewing an Image, Getting Image Resolution, Looking at Pixel Values, Converting Color Space, Saving an Image, Creating Basic Drawings, Doing Gamma Correction. Rotating, Shifting, and Scaling Images, Determining Structural Similarity.

from skimage import io
import skimage
#dir(skimage)
dir(io)

[ 'imread',
 'imsave',
 'imshow',
 'show',
......]

Uploading and Viewing an Image

from skimage import io
# Load image (supports jpg, png, tif, etc.)
img = io.imread("images/horses.jpg") #//local side
#Url path
#img = io.imread("https://assets.bucketlistly.blog/sites/5adf778b6eabcc00190b75b1/assets/6075182186d092000b192cee/best-free-travel-images-image-2.jpg") 
#img01=img.T

# Show image
io.imshow(img)
io.show()

Getting Image Resolution

print("Image resolution:", img.shape)  
# (height, width, channels)

Looking at Pixel Values

# Access a pixel (row=100, col=150, channel=RGB)
print("Pixel value:", img[100, 150])  

# Change a pixel
img[100, 150] = [255, 0, 0]  # make it red

Converting Color Space

Some color spaces (channels)
The following represents a few popular channels/color spaces for
an image: RGB, HSV, XYZ, YUV, YIQ, YPbPr, YCbCr, and YDbDr. We can use Affine
mappings to go from one color space to another. The following matrix represents the linear
mapping from the RGB to YIQ color space:

from skimage import color
dir(color)

['rgb2gray',
 'rgb2hed',
 'rgb2hsv',
......... 
]

from skimage import color
img = io.imread("images/parrot.jpg")

gray_img = color.rgb2gray(img)        # RGB → Grayscale
hsv_img = color.rgb2hsv(img)          # RGB → HSV
lab_img = color.rgb2lab(img)          # RGB → LAB

io.imshow(img)
io.show()

io.imshow(gray_img)
io.show()
io.imshow(hsv_img)
io.show()
io.imshow(lab_img)
io.show()

Saving an Image

import numpy as np
from skimage import io

lab_norm = (lab_img - lab_img.min()) / (lab_img.max() - lab_img.min())  # scale to [0,1]
lab_uint8 = (lab_norm * 255).astype(np.uint8)

io.imsave("lab_img.jpg", lab_uint8)

or 

from skimage import exposure, img_as_ubyte, io
# # Rescale lab_img to [0,1] before converting
lab_rescaled = exposure.rescale_intensity(lab_img, in_range='image', out_range=(0,1))
io.imsave("lab_img.jpg", img_as_ubyte(lab_rescaled))

Creating Basic Drawings

from skimage import draw
dir(draw) 

['_bezier_segment',
 'bezier_curve',
 'circle_perimeter',
 'circle_perimeter_aa',
 'disk',
 'ellipse',
 'ellipse_perimeter',
 'ellipsoid',
 'ellipsoid_stats',
 'line',
 'line_aa',
 'line_nd',
 'polygon',
 'polygon2mask',
 'polygon_perimeter',
 'random_shapes',
 'rectangle',
 'rectangle_perimeter',
 'set_color']

import numpy as np
from skimage.draw import line, rectangle, disk
from skimage import io, transform

# Load background image
background = io.imread("images/zebras.jpg")   # <-- replace with your image path
background = transform.resize(background, (200, 200), preserve_range=True).astype(np.uint8)

canvas = background.copy()

# Draw line
rr, cc = line(10, 10, 180, 180)
canvas[rr, cc] = [255, 0, 0]   # Red line

# Draw rectangle
rr, cc = rectangle(start=(50, 50), end=(120, 120))
canvas[rr, cc] = [0, 255, 0]   # Green rectangle

# Draw circle
rr, cc = disk((150, 150), 20)
canvas[rr, cc] = [0, 0, 255]   # Blue circle

# Show result
io.imshow(canvas)
io.show()

Doing Gamma Correction

where c and g are positive constants. Sometimes Eq. (6) is written as S = C (r +ε) γ to account for an offset

(that is, a measurable output when the input is zero). Plots of s versus r for various values of γ are shown in

Figure. As in the case of the log transformation, power-law curves with fractional values of γ map a narrow

range of dark input values into a wider range of output values, with the opposite being true for higher values

of input levels. Unlike the log function, however, we notice here a family of possible transformation curves

obtained simply by varying γ.

In Fig that curves generated with values of γ>1 have exactly The opposite effect as those generated

with values of γ<1. Finally, we Note that Eq. (6) reduces to the identity transformation when

c=γ=1.

 

 

Fig: Plot of the equation S = crγ for various values of γ (c =1 in all cases).

This type of transformation is used for enhancing images for different type of display devices. The

gamma of different display devices is different. For example Gamma of CRT lies in between of

1.8 to 2.5, that means the image displayed on CRT is dark.

Varying gamma (γ) obtains family of possible transformation curves S = C* r γ

Here C and γ are positive constants. Plot of S versusr for various values of γ

is γ > 1 compresses dark values

Expands bright values

γ< 1(similar to Logtransformation)

Expands dark values

Compresses bright values

When C = γ = 1 , it reduces to identity transformation .

 

from skimage import exposure

gamma_corrected = exposure.adjust_gamma(img, gamma=1)  # >1 = darker, <1 = brighter
io.imshow(gamma_corrected)
io.show() 

Rotating, Shifting, and Scaling Images

row. It does not mean that these are the actual values of physical coordinates when the image

was sampled.

 

 

 

 

Thus the right side of the matrix represents a digital element, pixel or pel. The matrix can be

represented in the following form as well. The sampling process may be viewed as partitioning the

xy plane into a grid with the coordinates of the center of each grid being a pair of elements from

the Cartesian products Z2 which is the set of all ordered pair of elements (Zi, Zj) with Zi and Zj

being integers from Z. Hence f(x,y) is a digital image if gray level (that is, a real number from the

set of real number R) to each distinct pair of coordinates (x,y). This functional assignment is the

quantization process. If the gray levels are also integers, Z replaces R, the and a digital image

become a 2D function whose coordinates and she amplitude value are integers. Due to processing

storage and hardware consideration, the number gray levels typically is an integer power of2.

L=2k

Then, the number, b, of bites required to store a digital image is b=M *N* k When M=N, the

equation become b=N2 *k

When an image can have 2k gray levels, it is referred to as “k- bit”. An image with 256 possible

gray levels is called an “8- bit image” (256=28 ).

 

 

Rotating

In linear algebra, a rotation matrix is a transformation matrix that is used to perform a rotation in Euclidean space. For example, using the convention below, the matrix

Clock Wise

Anti - Clock Wise

This rotates column vectors by means of the following matrix multiplication,

Says For ClockWise Rotation

Shift An Image

Cal :

from skimage import transform

rotated = transform.rotate(img, angle=45)  # rotate 45°
shifted = transform.warp(img, transform.AffineTransform(translation=(50, 30)))
scaled = transform.rescale(img, 0.5, channel_axis=-1)  # 50% size
plt.imshow(rotated)
plt.axis('off')
plt.show()

Determining Structural Similarity (SSIM)

from skimage.metrics import structural_similarity as ssim
from skimage import io

# Load grayscale images
img1 = io.imread("images/parrot.jpg", as_gray=True)
img2 = io.imread("images/parrot.jpg", as_gray=True)

# Compute SSIM
score, diff = ssim(img1, img2, full=True, data_range=img1.max() - img1.min())

print("SSIM:", score)  # 1.0 = identical

Toggle Button

E:\android\MyApplication\app\src\main\res\layout\activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity"
    android:orientation="vertical"
    >


    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textColor="#FF5722"
        android:textSize="30sp"
        android:textStyle="bold"
        android:textAllCaps="true"
        android:padding="10dp"
        android:layout_margin="10dp"
        android:gravity="center"
        android:layout_gravity="center"
        android:id="@+id/tv1"
        />

    <ToggleButton
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textColor="#FF5722"
        android:textSize="30sp"
        android:textStyle="bold"
        android:textAllCaps="true"
        android:padding="10dp"
        android:layout_margin="10dp"
        android:gravity="center"
        android:layout_gravity="center"
        android:id="@+id/toggle"></ToggleButton>

</LinearLayout>

E:\android\MyApplication\app\src\main\java\com\example\myapplication\MainActivity.kt

package com.example.myapplication
import android.os.Bundle
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity
import android.widget.TextView
import android.widget.ToggleButton

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        var tv: TextView?=null
        var toogle: ToggleButton?=null

        enableEdgeToEdge()
        setContentView(R.layout.activity_main)


        tv = findViewById(R.id.tv1)

        toogle=findViewById(R.id.toggle)
        toogle!!.setOnClickListener{
            if(toogle!!.isChecked)
                tv!!.text=("TON")
            else
                tv!!.text=("TOFF")
        }

    }
}

Output:

https://www.jsonschema2pojo.org/

https://androindian.com/

E:\android\android apps\APIIntegration\app\src\main\AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">

    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

    <application
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.APIIntegration"
        tools:targetApi="31">
        <activity
            android:name=".MenuPage"
            android:exported="false" />
<!--        <activity-->
<!--            android:name=".DashBoard"-->
<!--            android:exported="false" />-->
        <activity
            android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity> <!-- Declare your activities here -->
        <activity android:name=".Login" />
    </application>

</manifest>

E:\android\android apps\APIIntegration\app\src\main\java\com\example\apiintegration\ConnectionChecking.kt

package com.example.apiintegration

import android.content.Context
import android.net.ConnectivityManager
import android.net.NetworkCapabilities
import android.os.Build

class ConnectionChecking {

    fun isConnectingToInternet(context: Context): Boolean {
        val connectivityManager = context.getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            val network = connectivityManager.activeNetwork ?: return false
            val networkCapabilities = connectivityManager.getNetworkCapabilities(network) ?: return false
            return networkCapabilities.hasCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET)
        } else {
            val networkInfo = connectivityManager.activeNetworkInfo
            return networkInfo != null && networkInfo.isConnected
        }
    }
}

E:\android\android apps\APIIntegration\app\src\main\java\com\example\apiintegration\CustomAdapter.kt

package com.example.apiintegration
import android.content.Context
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.ImageView
import android.widget.TextView
import android.widget.Toast
import androidx.recyclerview.widget.RecyclerView
//import com.squareup.picasso.Picasso
import com.squareup.picasso.Picasso

class CustomAdapter(private val context: Context, private val adpData: List<ListRes>)
    : RecyclerView.Adapter<CustomAdapter.MyViewHolder>() {

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MyViewHolder {
        val view = LayoutInflater.from(parent.context).inflate(R.layout.custom, parent, false)
        return MyViewHolder(view)
    }

    override fun onBindViewHolder(holder: MyViewHolder, position: Int) {
        val item = adpData[position]
        holder.id?.text = item.id.toString()
        holder.mail?.text = item.user
        holder.fname?.text = item.name
        holder.lname?.text = item.place
        holder.phonenumber?.text = item.phonenumber
        // If you want to load image:
        //Picasso.get().load(item.img).into(holder.iv)
        Picasso.with(context).load(adpData.get(holder.adapterPosition).img).into(holder.iv)

        holder.iv?.setOnClickListener {
            Toast.makeText(context,"Clicked ${item.name}",Toast.LENGTH_LONG).show()
        }
    }

    override fun getItemCount(): Int = adpData.size

    inner class MyViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
        var id: TextView? = itemView.findViewById(R.id.id1)
        var mail: TextView? = itemView.findViewById(R.id.email)
        var fname: TextView? = itemView.findViewById(R.id.firtsname)
        var lname: TextView? = itemView.findViewById(R.id.lastname)
        var phonenumber: TextView? = itemView.findViewById(R.id.phonenumber)
        var iv: ImageView? = itemView.findViewById(R.id.iv)
    }
}

E:\android\android apps\APIIntegration\app\src\main\java\com\example\apiintegration\ListRes.java

package com.example.apiintegration;
//import javax.annotation.Generated;
import com.google.gson.annotations.Expose;
import com.google.gson.annotations.SerializedName;

public class ListRes {
    @SerializedName("id")
    @Expose
    private Integer id;
    @SerializedName("user")
    @Expose
    private String user;
    @SerializedName("name")
    @Expose
    private String name;
    @SerializedName("phonenumber")
    @Expose
    private String phonenumber;
    @SerializedName("place")
    @Expose
    private String place;
    @SerializedName("workinformation")
    @Expose
    private String workinformation;
    @SerializedName("img")
    @Expose
    private String img;
    @SerializedName("Remarks")
    @Expose
    private String remarks;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getUser() {
        return user;
    }

    public void setUser(String user) {
        this.user = user;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getPhonenumber() {
        return phonenumber;
    }

    public void setPhonenumber(String phonenumber) {
        this.phonenumber = phonenumber;
    }

    public String getPlace() {
        return place;
    }

    public void setPlace(String place) {
        this.place = place;
    }

    public String getWorkinformation() {
        return workinformation;
    }

    public void setWorkinformation(String workinformation) {
        this.workinformation = workinformation;
    }

    public String getImg() {
        return img;
    }

    public void setImg(String img) {
        this.img = img;
    }

    public String getRemarks() {
        return remarks;
    }

    public void setRemarks(String remarks) {
        this.remarks = remarks;
    }

}

E:\android\android apps\APIIntegration\app\src\main\java\com\example\apiintegration\Login.kt

package com.example.apiintegration
import android.content.Intent
import android.content.SharedPreferences
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.util.Log
import android.widget.Toast
import androidx.databinding.DataBindingUtil
import com.example.apiintegration.databinding.ActivityLoginBinding
import com.google.gson.JsonParser
import org.json.JSONObject
import retrofit2.Call
import retrofit2.Response
import retrofit2.Retrofit
import retrofit2.converter.gson.GsonConverterFactory
class Login : AppCompatActivity() {
    var binding: ActivityLoginBinding?=null
    val TAG = "Login"

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding=
            DataBindingUtil.setContentView(this,R.layout.activity_login)
        binding?.newuser?.setOnClickListener {
            var intent= Intent(this@Login,MenuPage::class.java)
            startActivity(intent)
        }
        binding?.login?.setOnClickListener {
            var uemail=binding?.email?.editText?.text.toString().trim()
            var upass=binding?.password?.editText?.text.toString().trim()

            //1
            var jsonObject= JSONObject()
            jsonObject.put("username",uemail)
            jsonObject.put("password",upass)

            //2
            var retrofit= Retrofit.Builder().
            baseUrl("https://7001.sites.marrichet.com/api/").
            addConverterFactory(GsonConverterFactory.create()).build()


            //3
            var retroInterface=retrofit.create(SampleProjectInterface::class.java)
            var requestjson=
                JsonParser().parse(jsonObject.toString()).asJsonObject
            var logsponsecall=retroInterface.loginUser(requestjson)

            logsponsecall?.enqueue(object :
                retrofit2.Callback<LoginResponse>{

                override fun onResponse(call: Call<LoginResponse>, response: Response<LoginResponse>) {
                    val loginResponse = response.body()
                    Log.d(TAG, "API Response: $loginResponse")

                    val token = loginResponse?.token
                    if (!token.isNullOrBlank()) {
                        Toast.makeText(this@Login, "Login successful!", Toast.LENGTH_SHORT).show()

                        val intent = Intent(this@Login, MenuPage::class.java)
                        startActivity(intent)

                        val sharedPreferences = getSharedPreferences("Login", MODE_PRIVATE)
                        val editor = sharedPreferences.edit()
                        editor.putString("email", uemail)
                        editor.putString("password", upass)
                        editor.putString("token", token)
                        editor.apply()
                    } else {
                        Toast.makeText(this@Login, "Login failed: Invalid token", Toast.LENGTH_LONG).show()
                    }
                }


                override fun onFailure(call: Call<LoginResponse>, t:
                Throwable) {

                    Log.d(TAG, "Request JSON onFailure: $call,$t")
                    Toast.makeText(this@Login,""+t,
                        Toast.LENGTH_LONG).show()
                }
            })
        }
    }
}

E:\android\android apps\APIIntegration\app\src\main\java\com\example\apiintegration\LoginResponse.kt

package com.example.apiintegration

import com.google.gson.annotations.Expose
import com.google.gson.annotations.SerializedName

class LoginResponse {
    @SerializedName("token")
    @Expose
    var token: String? = null

    @SerializedName("username")
    @Expose
    var username: String? = null

    @SerializedName("passwordadd")
    @Expose
    var passwordadd: String? = null

    @SerializedName("img")
    @Expose
    var img: String? = null
}

E:\android\android apps\APIIntegration\app\src\main\java\com\example\apiintegration\MainActivity.kt

package com.example.apiintegration
import android.content.Intent
import android.os.Bundle
import android.widget.Toast
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity
import androidx.core.view.ViewCompat
import androidx.core.view.WindowInsetsCompat
import androidx.databinding.DataBindingUtil
import com.example.apiintegration.databinding.ActivityMainBinding
import com.google.gson.JsonParser
import org.json.JSONObject
import retrofit2.Call
import retrofit2.Callback
import retrofit2.Retrofit
import retrofit2.converter.gson.GsonConverterFactory
import retrofit2.Response
import android.util.Log

class MainActivity : AppCompatActivity() {

    var binding: ActivityMainBinding?=null
    val TAG = "MainActivity"
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding= DataBindingUtil.setContentView(this,R.layout.activity_main)



        binding?.register?.setOnClickListener{
            var name=binding?.username?.editText?.text.toString().trim()
//            var email=binding?.email?.editText?.text.toString().trim()
            var password=binding?.passwod?.editText?.text.toString().trim()

            //1
            var jsonObject= JSONObject()
            // jsonObject.put("key is from api","valuee from xml")
            jsonObject.put("username",name)
            jsonObject.put("password",password)
//            jsonObject.put("email",email)

            //2
            var retrofit= Retrofit.Builder().
            baseUrl("https://7001.sites.marrichet.com/api/")
                .addConverterFactory(GsonConverterFactory.create()).build()
            //3
            var retroInterface=retrofit.create(SampleProjectInterface::class.java)

            var regisetercall: Call<RegisterResponse>

            //6
            val `xyz` = JsonParser().parse(jsonObject.toString()).asJsonObject

            Log.d(TAG, "Request JSON: $xyz")

            //8
            val regResponseCall = retroInterface.createUser(`xyz`)

            regResponseCall?.enqueue(object : Callback<RegisterResponse?>{
                override fun onResponse(
                    call: Call<RegisterResponse?>,
                    response: Response<RegisterResponse?>

                ) {
                    Log.d(TAG, "Response received: $response,$call")
                    if (response.isSuccessful && response.body() != null) {
                        val registeredUsername = response.body()?.username
                        Toast.makeText(this@MainActivity, "Registered: $registeredUsername", Toast.LENGTH_LONG).show()
                        Log.d(TAG, "if black Response received: $response,$call")

                      // Navigate to Login activity or next step if needed

//                      startActivity(Intent(this@MainActivity, LoginActivity::class.java))
                    } else {
                        Toast.makeText(this@MainActivity, "Registration failed: ${response.errorBody()?.string()}", Toast.LENGTH_LONG).show()
                        Log.d(TAG, "else black Response received: $response,$call")

                        var intent= Intent(this@MainActivity, Login::class.java)
                        startActivity(intent)

                    }

                }

                override fun onFailure(call: Call<RegisterResponse?>, t: Throwable) {
                    Log.d(TAG, "OnFailure: $call,$t")
                    Toast.makeText(this@MainActivity,""+t.toString(),Toast.LENGTH_LONG).show()
                }
            })


    }

    }
}

E:\android\android apps\APIIntegration\app\src\main\java\com\example\apiintegration\MenuPage.kt

package com.example.apiintegration

import android.content.Intent
import android.os.Bundle
import android.util.Log
import android.widget.LinearLayout
import android.widget.Toast
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity
import androidx.core.view.ViewCompat
import androidx.core.view.WindowInsetsCompat
import androidx.databinding.DataBindingUtil
import androidx.recyclerview.widget.LinearLayoutManager
import com.example.apiintegration.databinding.ActivityMainBinding
import com.example.apiintegration.databinding.ActivityMenuPageBinding
import com.google.gson.JsonParser
import retrofit2.Call
import retrofit2.Callback
import retrofit2.Response
import retrofit2.Retrofit
import retrofit2.converter.gson.GsonConverterFactory

class MenuPage : AppCompatActivity() {

    var binding:ActivityMenuPageBinding?=null
    val TAG = "MenuPage"
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        enableEdgeToEdge()

//        setContentView(R.layout.activity_menu_page)
        binding=DataBindingUtil.setContentView(this,R.layout.activity_menu_page)


        var sharedPreferences=getSharedPreferences("Login", MODE_PRIVATE)
        var s1=sharedPreferences.getString("email",null)
        var s2=sharedPreferences.getString("pass",null)
        Toast.makeText(this@MenuPage, "" + s1 + s2, Toast.LENGTH_LONG).show()

        binding?.logout?.setOnClickListener{
            var editor=sharedPreferences.edit()
            editor.clear()
            editor.apply()


            // Redirect to Login (MainActivity)
            val intent = Intent(this@MenuPage, Login::class.java)
            startActivity(intent)
            finish()  // close MenuPage so user can't go back with back button
        }


        //2
        var retrofit= Retrofit.Builder().
        baseUrl("https://7001.sites.marrichet.com/api/")
            .addConverterFactory(GsonConverterFactory.create()).build()
        //3
        var retroInterface=retrofit.create(SampleProjectInterface::class.java)

        //6
        //var regisetercall: Call<RegisterResponse>

        //val datajson = JsonParser().parse(jsonObject.toString()).asJsonObject

        //Log.d(TAG, "Request JSON: $datajson")

        //8
        //val regResponseCall = retroInterface.createUser(datajson)
        val regResponseCall = retroInterface.loadData()


        regResponseCall?.enqueue(object : Callback<List<ListRes>?> {
            override fun onResponse(
                call: Call<List<ListRes>?>,
                response: Response<List<ListRes>?>
            ) {
                Log.d(TAG, "API Response: ${response.body()}")

                val linearLayoutManager = LinearLayoutManager(this@MenuPage,
                    LinearLayoutManager.VERTICAL, false)
                binding?.rec?.layoutManager = linearLayoutManager

                val customAdapter = CustomAdapter(this@MenuPage, response.body() ?: emptyList())
                binding?.rec?.adapter = customAdapter
            }

            override fun onFailure(call: Call<List<ListRes>?>, t: Throwable) {
                Log.d(TAG, "OnFailure: $call,$t")
                Toast.makeText(this@MenuPage,""+t.toString(),Toast.LENGTH_LONG).show()
            }
        })

    }



}

E:\android\android apps\APIIntegration\app\src\main\java\com\example\apiintegration\RegisterResponse.kt

package com.example.apiintegration


//✅ 1. Ensure You're Using the Right Shortcut
//For Windows/Linux:
//Ctrl + Alt + Shift + K

import com.google.gson.annotations.Expose
import com.google.gson.annotations.SerializedName

//https://www.jsonschema2pojo.org/
class RegisterResponse {
    @SerializedName("username")
    @Expose
    var username: String? = null
}

E:\android\android apps\APIIntegration\app\src\main\java\com\example\apiintegration\SampleProjectInterface.kt

package com.example.apiintegration

import com.google.gson.JsonObject
import retrofit2.Call
import retrofit2.http.Body
import retrofit2.http.GET
import retrofit2.http.Headers
import retrofit2.http.POST

public interface SampleProjectInterface {


    @Headers("Content-Type: application/json")
    @POST("register/")
    fun createUser(@Body jsonObject: JsonObject): Call<RegisterResponse>?

    @Headers("Content-Type:application/json")
    @POST("login/")
    fun loginUser(@Body jsonObject: JsonObject): Call<LoginResponse>

//    https://7001.sites.marrichet.com/api/contactbookapi/

    @Headers("Content-Type:application/json")
    @GET("contactbookapi/")
    fun loadData(): Call<List<ListRes>>



}

E:\android\android apps\APIIntegration\app\src\main\java\com\example\apiintegration\Support.kt

package com.example.apiintegration
import com.google.gson.annotations.Expose
import com.google.gson.annotations.SerializedName
class Support {
    @SerializedName("url")
    @Expose
    var url: String? = null
    @SerializedName("text")
    @Expose
    var text: String? = null
}

E:\android\android apps\APIIntegration\app\src\main\res\layout\activity_dash_board.xml

<?xml version="1.0" encoding="utf-8"?>
<layout>
    <LinearLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".DashBoard"
        android:orientation="vertical">
        <Button
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/logout"
            android:layout_margin="10dp"
            android:text="Logout"/>
        <androidx.recyclerview.widget.RecyclerView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_margin="10dp"
            android:id="@+id/rec"/>
    </LinearLayout>
</layout>

E:\android\android apps\APIIntegration\app\src\main\res\layout\activity_login.xml

<?xml version="1.0" encoding="utf-8"?>
<layout>
    <RelativeLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".Login">
        <androidx.cardview.widget.CardView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_margin="10dp"
            android:layout_centerHorizontal="true"
            android:layout_centerVertical="true">
            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:orientation="vertical"
                android:layout_margin="5dp">
                <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="Login Here"
                    android:layout_gravity="center" />
                <com.google.android.material.textfield.TextInputLayout
                    android:id="@+id/email"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:hint="email"
                    android:layout_margin="5dp"
                    style="@style/Widget.MaterialComponents.TextInputLayout.OutlinedBox">
                    <com.google.android.material.textfield.TextInputEditText
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"
                        />
                </com.google.android.material.textfield.TextInputLayout>
                <com.google.android.material.textfield.TextInputLayout
                    android:id="@+id/password"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:hint="Password"
                    android:layout_margin="5dp"
                    style="@style/Widget.MaterialComponents.TextInputLayout.OutlinedBox">
                    <com.google.android.material.textfield.TextInputEditText
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"
                        />
                </com.google.android.material.textfield.TextInputLayout>
                <Button
                    android:id="@+id/login"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="Login"
                    android:padding="5dp"
                    android:layout_margin="5dp"
                    android:layout_gravity="center"
                    />
                <TextView
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:id="@+id/newuser"
                    android:text="New User Register Here"
                    android:textSize="25sp"/>
            </LinearLayout>
        </androidx.cardview.widget.CardView>
    </RelativeLayout>
</layout>

E:\android\android apps\APIIntegration\app\src\main\res\layout\activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<layout>
    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".MainActivity"
        android:id="@+id/main"
        android:orientation="vertical">

        <androidx.cardview.widget.CardView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_margin="5dp"
            android:layout_centerHorizontal="true"
            android:layout_centerVertical="true">

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_margin="5dp"
                android:orientation="vertical">

                <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="Register here"
                    />

                <com.google.android.material.textfield.TextInputLayout
                    android:id="@+id/username"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:hint="UserName"
                    android:layout_margin="5dp">

                    <com.google.android.material.textfield.TextInputEditText
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"
                        />

                </com.google.android.material.textfield.TextInputLayout>

                <com.google.android.material.textfield.TextInputLayout
                    android:id="@+id/passwod"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:hint="Password"
                    android:layout_margin="5dp">

                    <com.google.android.material.textfield.TextInputEditText
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"
                        />

                </com.google.android.material.textfield.TextInputLayout>

                <Button
                    android:id="@+id/register"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="Register"
                    android:layout_gravity="center"
                    />
            </LinearLayout>
        </androidx.cardview.widget.CardView>

    </RelativeLayout>
</layout>

E:\android\android apps\APIIntegration\app\src\main\res\layout\activity_menu_page.xml

<?xml version="1.0" encoding="utf-8"?>
<layout>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MenuPage"
    android:orientation="vertical"
    >
    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="logout"
        android:id="@+id/logout"
        />

    <androidx.recyclerview.widget.RecyclerView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/rec"/>

</LinearLayout>
</layout>

E:\android\android apps\APIIntegration\app\src\main\res\layout\custom.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal"
    android:padding="8dp">

    <!-- Avatar Image -->
    <ImageView
        android:id="@+id/iv"
        android:layout_width="60dp"
        android:layout_height="60dp"
        android:scaleType="centerCrop"
        android:src="@mipmap/ic_launcher"
        android:layout_marginEnd="8dp" />

    <!-- Text Container -->
    <LinearLayout
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:orientation="vertical">

        <TextView
            android:id="@+id/id1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="ID"
            android:textStyle="bold"
            android:textSize="14sp" />

        <TextView
            android:id="@+id/email"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="User Email"
            android:textSize="14sp" />

        <TextView
            android:id="@+id/firtsname"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Name"
            android:textSize="14sp" />

        <TextView
            android:id="@+id/lastname"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Place"
            android:textSize="14sp" />

        <TextView
            android:id="@+id/phonenumber"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="phonenumber"
            android:textSize="14sp" />


    </LinearLayout>

</LinearLayout>

E:\android\android apps\APIIntegration\app\build.gradle.kts

android {
    compileSdk = 35
    defaultConfig {
        targetSdk = 35
    }

    buildFeatures {
        dataBinding = true
    }
}


dependencies {
    implementation(libs.androidx.core.ktx)
    implementation(libs.androidx.appcompat)
    implementation(libs.material)
    implementation(libs.androidx.activity)
    implementation(libs.androidx.constraintlayout)

    implementation("com.squareup.retrofit2:retrofit:2.11.0")
    implementation("com.squareup.retrofit2:converter-gson:2.11.0")
    implementation ("com.google.code.gson:gson:2.8.9")
    implementation ("com.github.bumptech.glide:glide:4.16.0")
    implementation ("com.squareup.picasso:picasso:2.5.2")

    testImplementation(libs.junit)
    androidTestImplementation(libs.androidx.junit)
    androidTestImplementation(libs.androidx.espresso.core)
}

Output:

Scale-invariant feature transform

Scale-invariant feature transform (SIFT) descriptors provide an alternative representation for image regions. They are very useful for matching images. As demonstrated earlier, simple corner detectors work well when the images to be matched are similar in nature (with respect to scale, orientation, and so on). But if they have different scales and rotations, the SIFT descriptors are needed to be used to match them. SIFT is not only just scale invariant, but it still obtains good results when rotation, illumination, and viewpoints of the images change as well.

Let's discuss the primary steps involved in the SIFT algorithm that transforms image content into local feature coordinates that are invariant to translation, rotation, scale, and other imaging parameters.

Algorithm to compute SIFT descriptors

Scale-space extrema detection: Search over multiple scales and image locations, the location and characteristic scales are given by DoG detector Keypoint localization: Select keypoints based on a measure of stability, keep only the strong interest points by eliminating the low-contrast and edge keypoints Orientation assignment: Compute the best orientation(s) for each keypoint region, which contributes to the stability of matching Keypoint descriptor computation: Use local image gradients at selected scale and rotation to describe each keypoint region

As discussed, SIFT is robust with regard to small variations in illumination (due to gradient and normalization), pose (small affine variation due to orientation histogram), scale (by DoG), and intra-class variability (small variations due to histograms).

With opencv and opencv-contrib

We will first construct a SIFT object and then use the detect() method to compute the keypoints in an image. Every keypoint is a special feature, and has several attributes. For example, its (x, y) coordinates, angle (orientation), response (strength of keypoints), size of the meaningful neighborhood, and so on.

import cv2
import numpy as np
import matplotlib.pyplot as plt

# Load grayscale image
img_path = "images/monalisa.jpg"
img = cv2.imread(img_path, cv2.IMREAD_GRAYSCALE)
if img is None:
    raise FileNotFoundError(f"Image not found at {img_path}")

# Create SIFT detector
sift = cv2.SIFT_create()
keypoints, descriptors = sift.detectAndCompute(img, None)

# Draw keypoints
img_kp = cv2.drawKeypoints(img, keypoints, None, flags=cv2.DRAW_MATCHES_FLAGS_DRAW_RICH_KEYPOINTS)

# Convert grayscale to RGB for matplotlib
img_kp_rgb = cv2.cvtColor(img_kp, cv2.COLOR_BGR2RGB)

# Display
plt.figure(figsize=(10, 8))
plt.imshow(img_kp_rgb)
plt.axis('off')
plt.title(f"SIFT Keypoints (Total: {len(keypoints)})")
plt.show()

# Print descriptor info
print("Number of keypoints:", len(keypoints))
print("Descriptor shape:", descriptors.shape)

RANSAC algorithm

In this example, we will match an image with its affine transformed version; they can be considered as if they were taken from different view points. The following steps describe the image matching algorithm:

1. First, we will compute the interest points or the Harris Corners in both the images.

2. A small space around the points will be considered, and the correspondences inbetween the points will then be computed using a weighted sum of squared differences. This measure is not very robust, and it's only usable with slight viewpoint changes.

3. A set of source and corresponding destination coordinates will be obtained once the correspondences are found; they are used to estimate the geometric transformations between both the images.

4. A simple estimation of the parameters with the coordinates is not enough—many of the correspondences are likely to be faulty.

5. The RANdom SAmple Consensus (RANSAC) algorithm is used to robustly estimate the parameters, first by classifying the points into inliers and outliers, and then by fitting the model to inliers while ignoring the outliers, in order to find matches consistent with an affine transformation. The next code block shows how to implement the image matching using the Harris Corner features:

# Read and prepare image
temple = rgb2gray(img_as_float(imread('../images/temple.JPG')))
image_original = np.zeros(list(temple.shape) + [3])
image_original[..., 0] = temple
gradient_row, gradient_col = np.mgrid[0:image_original.shape[0], 0:image_original.shape[1]] / float(image_original.shape[0])
image_original[..., 1] = gradient_row
image_original[..., 2] = gradient_col
image_original = rescale_intensity(image_original)
image_original_gray = rgb2gray(image_original)

# Apply affine transform
affine_trans = AffineTransform(scale=(0.8, 0.9), rotation=0.1, translation=(120, -20))
image_warped = warp(image_original, affine_trans.inverse, output_shape=image_original.shape)
image_warped_gray = rgb2gray(image_warped)

# Detect corners
coords_orig = corner_peaks(corner_harris(image_original_gray), threshold_rel=0.01, min_distance=5)
coords_warped = corner_peaks(corner_harris(image_warped_gray), threshold_rel=0.01, min_distance=5)

# Refine corners to subpixel accuracy
coords_orig_subpix = corner_subpix(image_original_gray, coords_orig, window_size=9)
coords_warped_subpix = corner_subpix(image_warped_gray, coords_warped, window_size=9)

# Plot results
fig, axes = plt.subplots(1, 2, figsize=(20, 10))
axes[0].imshow(image_original_gray, cmap='gray')
axes[0].plot(coords_orig_subpix[:, 1], coords_orig_subpix[:, 0], 'r.', markersize=5)
axes[0].set_title('Original image with corners')
axes[0].axis('off')

axes[1].imshow(image_warped_gray, cmap='gray')
axes[1].plot(coords_warped_subpix[:, 1], coords_warped_subpix[:, 0], 'r.', markersize=5)
axes[1].set_title('Warped image with corners')
axes[1].axis('off')

plt.show()

Image Classification Using CNNs

CNNs are deep neural networks for which the primarily used input is images. CNNs learn the filters (features) that are hand-engineered in traditional algorithms. This independence from prior knowledge and human effort in feature design is a major advantage. They also reduce the number of parameters to be learned with their shared-weights architecture and possess translation invariance characteristics. In the next subsection, we'll discuss the general architecture of a CNN and how it works.

Conv or pooling or FC layers – CNN architecture and how it works

The next screenshot shows the typical architecture of a CNN. It consists of one or more convolutional layer, followed by a nonlinear ReLU activation layer, a pooling layer, and, finally, one (or more) fully connected (FC) layer, followed by an FC softmax layer, for example, in the case of a CNN designed to solve an image classification problem.

There can be multiple convolution ReLU pooling sequences of layers in the network, making the neural network deeper and useful for solving complex image processing tasks, as seen in the following diagram:

Convolutional layer

The main building block of CNN is the convolutional layer. The convolutional layer consists of a bunch of convolution filters (kernels), which we already discussed in detail in Chapter 2(refere Text Book2), Sampling, Fourier Transform, and Convolution. The convolution is applied on the input image using a convolution filter to produce a feature map. On the left side is the input to the convolutional layer; for example, the input image. On the right is the convolution filter, also called the kernel. As usual, the convolution operation is performed by sliding this filter over the input. At every location, the sum of element-wise matrix multiplication goes into the feature map. A convolutional layer is represented by its width, height (the size of a filter is width x height), and depth (number of filters). Stride specifies how much the convolution filter will be moved at each step (the default value is 1). Padding refers to the layers of zeros to surround the input (generally used to keep the input and output image size the same, also known as same padding). The following screenshot shows how 3 x 3 x 3 convolution filters are applied on an RGB image, the first with valid padding and the second with the computation with two such filters with the size of the stride=padding=1

Pooling layer

After a convolution operation, a pooling operation is generally performed to reduce dimensionality and the number of parameters to be learned, which shortens the training time, requires less data to train, and combats overfitting. Pooling layers downsample each feature map independently, reducing the height and width, but keeping the depth intact. The most common type of pooling is max pooling, which just takes the maximum value in the pooling window. Contrary to the convolution operation, pooling has no parameters. It slides a window over its input and simply takes the max value in the window. Similar to a convolution, the window size and stride for pooling can be specified.

Non-linearity – ReLU layer

For any kind of neural network to be powerful, it needs to contain non-linearity. The result of the convolution operation is hence passed through the non-linear activation function. ReLU activation is used in general to achieve non-linearity (and to combat the vanishing gradient problem with sigmoid activation). So, the values in the final feature maps are not actually the sums, but the relu function applied to them.

FC layer

After the convolutional and pooling layers, generally a couple of FC layers are added to wrap up the CNN architecture. The output of both convolutional and pooling layers are 3D volumes, but an FC layer expects a 1D vector of numbers. So, the output of the final pooling layer needs to be flattened to a vector, and that becomes the input to the FC layer. Flattening is simply arranging the 3D volume of numbers into a 1D vector.

Dropout

Dropout is the most popular regularization technique for deep neural networks. Dropout is used to prevent overfitting, and it is typically used to increase the performance (accuracy) of the deep learning task on the unseen dataset. During training time, at each iteration, a neuron is temporarily dropped or disabled with some probability, p. This means all the input and output to this neuron will be disabled at the current iteration. This hyperparameter p is called the dropout rate, and it's typically a number around 0.5, corresponding to 50% of the neurons being dropped out.

Image Classification Using Machine Learning Approaches:Decision Trees,Support Vector Machines, Logistics Regression,Code,Important Terms

Decision Trees

-Supervised learning technique for classification or regression problems
-We create a model that predicts the value of a target variable by learning simple decision rules inferred from the data features
-Not as effective as the best supervised machine learning techniques
-Boosting and random forests  improve the performance
-Has several advantages + disadvantages

Advantages
-Simple to understand and to interpret + trees can be visualized
-No need for data preparations such as normalization or dummy variables
-Logarithmic O(logN) running time

Distadvantages
-Decision-tree learners can create over-complex trees that do not generalize to the data well  
-This is the problem of overfitting // pruning somethime helps
-Decision trees can be unstable because small variations in the data might result in a completely different tree being generated
-The problem of learning an optimal decision tree is known to be NP-complete !!!
-Practical decision-tree learning algorithms are based on heuristic algorithms such as the greedy algorithm
 

bias: error from misclassifications in the learning algorithm
    High bias  the algorithm misses the relevant relationships
            between features and target outputs !!!

        ERROR DUE TO MODEL MISMATCH 

variance: error from sensitivity to small changes in the training set
        High variance  can cause overfitting

        VARIATION DUE TO TRAINING SAMPLE AND RANDOMIAZTION
 

Bias / variance tradeoff
    ~ we are not able to optimize both bias and variance at the same time
        
        low bias  high variance
        low variance  high bias

 

Pruning
-Usually decision trees are likely to overfit the data leading to poor test performance
-Smaller tree + fewer splits  better predictor at the cost of a little bias
-Better solution: grow a large tree and then prune it back to a smaller subtree
„weakest link pruning”

Random forests
Why is it good?
If one or a few features are very strong predictors for the response variable (target output), these features will be selected in many of the decision trees  they will become correlated
Huge advantage  at some point the variance stops decreasing no matter how many more trees we add to our random forest + it is not going to produce overfitting !!!
Boosting
-It can be used for classification and regression too
-Helps to reduce variance and bias !!!
-Bagging: creates multiple copies of the original data  constructs several decision trees on the copies  combining all the trees to make predictions
-THESE TREES ARE INDEPENDENT FROM EACH OTHER !!!
-Boosting: here the decision trees are grown sequentially  each tree is grown using information from previously grown trees
-THESE TREES ARE NOT INDEPENDENT FROM EACH OTHER !!!
-Can a set of weak learners create a single strong learner? 
-Yes, we can turn a weak learner into a strong learner !!!
-Fit a large decision tree to the data  overfitting
-The boosting algorithm learns slowly instead
-By fitting small trees we slowly improve the final result in cases when it does not perform well
 

import numpy as np
from scipy.cluster.hierarchy import linkage, dendrogram
import matplotlib.pyplot as plt

# Data points
x = np.array([[1,1],[1.5,1],[3,3],[4,4],[3,3.5],[3.5,4]])

# Scatter plot of data points
plt.scatter(x[:,0], x[:,1], s=50, color='blue')
plt.title("Data points")
plt.xlabel("X1")
plt.ylabel("X2")
plt.show()

# Compute hierarchical clustering (linkage)
linkage_matrix = linkage(x, method='single')  # "single" linkage

# Plot dendrogram
plt.figure(figsize=(8,5))
dendrogram(linkage_matrix, truncate_mode='none', leaf_rotation=45, leaf_font_size=10)
plt.title("Hierarchical Clustering Dendrogram")
plt.xlabel("Sample index")
plt.ylabel("Distance")
plt.show()

Support Vector Machines:

-Very popular and widely used supervised learning classification algorithm
-The great benefit: it can operates even in infinite dimensions !!!
-It defines a margin / boundary  between the data points in multidimensional space
-Goal: find a flat boundary ( „hyperplane” ) that leads to a homogeneous partition of the data
-A good separation is achieved by the hyperplane that has the largest distance to the nearest training-data point of any class since in general the larger the margin the lower the generalization error of the classifier
-So we have to maximize the margin
 

-Can be applied to almost everything
-Classifications or numerical predictions
-Widely used in pattern recognition
   -Identify cancer or genetic diseases 
    -Text classification: classify texts based on the language
    -Detecting rare events: earthquakes or engine failures
 

Non-linear spaces
-In many real-world applications, the relationships between variables are non-linear
-A key feature of SVMs is their ability to map the problem into a higher dimensional space using a process known as the „kernel trick”
-Non-linear relationship may suddenly appears to be quite linear

Maths:

https://chatgpt.com/s/t_68b5c22784e88191960e71fbffc4d2f5

f(x) = sign( _i=1^N Σ α_i y_i K(x_i, x) + b )

Here:

• Σ → summation

• α_i, y_i, x_i → subscripted

• K(x_i, x) → kernel function

• b → bias term

Optional: Showing Kernel types in

1️⃣ Linear Kernel

K(x_i, x_j) = x_i · x_j

2️⃣ Polynomial Kernel

K(x_i, x_j) = (x_i · x_j + c)^d

• c → constant (can be 0 or 1)

• d → degree of the polynomial

-SVMs with non-linear kernels add additional dimensions to the data in order to create separation in this way
-Kernel  trick  process of adding new features that express mathematical relationships between measured characteristics
-This allows the SVM to learn concepts that were not explicitly measured in the original data
 

Advantages
-SVM can be used for regression problems as well as for classifications
-Not overly influenced by noisy data
-Easier to use than neural networks
Disadvantages
-Finding the best model requires testing of various combinations of kernels and model parameters
-Quite slow  especially when the input dataset has a large number of features
-Black box model: very hard to understand !!!
 

import matplotlib.pyplot as plt
from sklearn import datasets, svm, metrics
from sklearn.metrics import accuracy_score

# The digits dataset
digits = datasets.load_digits()

#print("Digits\n", digits)

images_and_labels = list(zip(digits.images, digits.target))

n_samples = len(digits.images)
data = digits.images.reshape((n_samples, -1))
#print("Data\n",data)

# Create a classifier: a support vector classifier
classifier = svm.SVC(gamma=0.001)

# We learn the digits on the first half of the digits
trainTestSplit = int(n_samples*0.75)
classifier.fit(data[:trainTestSplit], digits.target[:trainTestSplit])

# Now predict the value of the digit on the second half:
expected = digits.target[trainTestSplit:]
predicted = classifier.predict(data[trainTestSplit:])

#print("Classification report for classifier %s:\n%s\n"
#% (classifier, metrics.classification_report(expected, predicted)))
print("Confusion matrix:\n%s" % metrics.confusion_matrix(expected, predicted))
print(accuracy_score(expected, predicted))


# let's test on the last few images
plt.imshow(digits.images[-2], cmap=plt.cm.gray_r, interpolation='nearest')
print("Prediction for test image: ", classifier.predict(data[-2].reshape(1,-1)))

plt.show()

Logistics Regression

p(y) = e^{(b₀ + b₁ x)} / (1 + e^{(b₀ + b₁ x)})

The p(x) = P(default=1 | balance = x ) is the probability of default when we
know the balance !!!
 

It has a value between 0 and 1

Logistic regression fits the b  and b   parameters, these are the
regression parameters

This fitted curve is not linear: we can make it linear with the help
of the logit transformation 
 

import numpy as np
from matplotlib import pyplot as plt
from sklearn.linear_model import LogisticRegression

# p i = 1 / 1 + exp[ - ( b0 + b1 * x )]

x1 = np.array([0,0.6,1.1,1.5,1.8,2.5,3,3.1,3.9,4,4.9,5,5.1])
y1 = np.array([0,0,0,0,0,0,0,0,0,0,0,0,0])

x2 = np.array([3,3.8,4.4,5.2,5.5,6.5,6,6.1,6.9,7,7.9,8,8.1])
y2 = np.array([1,1,1,1,1,1,1,1,1,1,1,1,1])

X = np.array([[0],[0.6],[1.1],[1.5],[1.8],[2.5],[3],[3.1],[3.9],[4],[4.9],[5],[5.1],[3],[3.8],[4.4],[5.2],[5.5],[6.5],[6],[6.1],[6.9],[7],[7.9],[8],[8.1]])
y = np.array([0,0,0,0,0,0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1])

plt.plot(x1,y1,'ro',color='blue')
plt.plot(x2,y2,'ro',color='red')

model = LogisticRegression()
model.fit(X,y)

print("b0 is:", model.intercept_)
print("b1 is:", model.coef_)

def logistic(classifier, x):
	return 1/(1+np.exp(-(model.intercept_ + model.coef_ * x)))
	
for i in range(1,120):
	plt.plot(i/10.0-2,logistic(model,i/10.0),'ro',color='green')

plt.axis([-2,10,-0.5,2])
plt.show()

# pred = model.predict_proba(1)
# print("Prediction: ", pred)
pred = model.predict_proba([[1]])
print("Prediction: ", pred)

Introduction to Real-Time Use Cases:

Few Real time Ways 

A fully convolutional model for detecting objects: YOLO (v2)

Deep segmentation with DeepLab (v3)

Transfer learning: what is it and when to use it

Deep style transfer with cv2 using a pretrained torch-based deep learning model

Introducing YOLO v2 :

YOLO, is a very popular and fully conventional algorithm that is used for detecting images. It gives a very high accuracy rate compared to other algorithms, and also runs in real time. As the name suggests, this algorithm looks only once at an image. This means that this algorithm requires only one forward propagation pass to make accurate predictions.

In this section, we will detect objects in images with a fully convolutional network (FCN) deep learning model. Given an image with some objects (for example, animals, cars, and so on), the goal is to detect objects in those images using a pre-trained YOLO model, with bounding boxes.

 Deep semantic segmentation with DeepLab V3+

In this section, we'll discuss how to use a deep learning FCN to perform semantic segmentation of an image. Before diving into further details, let's clear the basic concepts.

Semantic segmentation

Semantic segmentation refers to an understanding of an image at pixel level; that is, when we want to assign each pixel in the image an object class (a semantic label). It is a natural step in the progression from coarse to fine inference. It achieves fine-grained inference by making dense predictions that infer labels for every pixel so that each pixel is labeled with the class of its enclosing object or region.

Transfer learning – what it is, and when to use it

Transfer learning is a deep learning strategy that reuses knowledge gained from solving one problem by applying it to a different, but related, problem. For example, let's say we have three types of flowers, namely, a rose, a sunflower, and a tulip. We can use the standard pre-trained models, such as VGG16/19, ResNet50, or InceptionV3 models (pretrained on ImageNet with 1000 output classes, which can be found at https://gist. github.com/yrevar/942d3a0ac09ec9e5eb3a) to classify the flower images, but our model wouldn't be able to correctly identify them because these flower categories were not learned by the models. In other words, they are classes that the model is not aware of.

Transfer learning with Keras

Training of pre-trained models is done on many comprehensive image classification problems. The convolutional layers act as a feature extractor, and the fully connected (FC) layers act as classifiers, as shown in the following diagram, in the context of cat vs. dog image classification with a conv net:

1. Blending Two Images
 👉 Blend two images of the same size using weighted addition.

import cv2
import matplotlib.pyplot as plt

img1 = cv2.imread("images/parrot.jpg")
img2 = cv2.imread("images/antelops.jpeg")

# Resize second image to match first
img2 = cv2.resize(img2, (img1.shape[1], img1.shape[0]))

# Blend images
blended = cv2.addWeighted(img1, 0.7, img2, 0.3, 0)

# Convert BGR → RGB for matplotlib
blended_rgb = cv2.cvtColor(blended, cv2.COLOR_BGR2RGB)

plt.imshow(blended_rgb)
plt.axis('off')
plt.title("Blended Image")
plt.show()

2. Changing Contrast and Brightness

👉 Use cv2.convertScaleAbs().

Contrast

The contrast stretching operation takes a low-contrast image as input and stretches the narrower range of the intensity values to span a desired wider range of values in order to output a high-contrast output image, thereby enhancing the image's contrast. It is just a linear scaling function that is applied to image pixel values, and hence the image enhancement is less drastic (than its more sophisticated counterpart histogram equalization, to be described shortly). The following screenshot shows the point transformation function for contrast stretching:

As can be seen from the previous screenshot, the upper and lower pixel value limits (over which the image is to be normalized), need to be specified before the stretching can be performed (for example, for a gray-level image, the limits are often set to 0 and 255, in order for the output image to span the entire range of available pixel values). All we need to find is a suitable value of m from the CDF of the original image. The contrast stretching transform produces higher contrast than the original by darkening the levels below the value m (in other words, stretching the values toward the lower limit) in the original image and brightening the levels previous to value m (stretching the values toward the upper limit) in the original image. The following sections describe how to implement contraststretching using the PIL library

# # alpha: contrast, beta: brightness
# adjusted = cv2.convertScaleAbs(img1, alpha=1.5, beta=50)

# cv2.imshow("Contrast & Brightness", adjusted)
# cv2.waitKey(0)
import cv2
import matplotlib.pyplot as plt

# Load image
img1 = cv2.imread("images/parrot.jpg")

# Adjust contrast (alpha) and brightness (beta)
adjusted = cv2.convertScaleAbs(img1, alpha=1.5, beta=50)

# Convert BGR → RGB for matplotlib
adjusted_rgb = cv2.cvtColor(adjusted, cv2.COLOR_BGR2RGB)

# Display safely in notebook
plt.imshow(adjusted_rgb)
plt.axis('off')
plt.title("Contrast & Brightness Adjusted")
plt.show()

Smoothing Images:

Online Reference Source

Problem with Smoothing 
    -Does Not remove outlies(Noise)
    - Smooths edges(Blur)

The original of the pixel is included in the computation of the median of the filter are quite possible  because for certain types of random noise, the provide excellent noise reduction capabilities with considerably less blurring then smoothing filters of similar size. These are effective for bipolar and unipolar impulse noise.

E:\android\android apps\MyApplication2\app\src\main\AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">

    <application
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.MyApplication"
        tools:targetApi="31">
        <activity
            android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

E:\android\android apps\MyApplication2\app\src\main\res\layout\activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity"
    android:orientation="vertical"
    >
    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textColor="#FF5722"
        android:textSize="30sp"
        android:textStyle="bold"
        android:textAllCaps="true"
        android:padding="10dp"
        android:layout_margin="10dp"
        android:gravity="center"
        android:layout_gravity="center"
        android:id="@+id/tv1"
        />
    <CheckBox
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Android"
        android:textColor="#FF5722"
        android:textSize="30sp"
        android:textStyle="bold"
        android:textAllCaps="true"
        android:padding="10dp"
        android:layout_margin="10dp"
        android:gravity="center"
        android:layout_gravity="center"
        android:id="@+id/check"
        ></CheckBox>


</LinearLayout>

E:\android\android apps\MyApplication2\app\src\main\java\com\example\myapplication\MainActivity.kt

package com.example.myapplication

import android.os.Bundle
import android.widget.CheckBox
import android.widget.TextView
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity
import androidx.core.view.ViewCompat
import androidx.core.view.WindowInsetsCompat

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        var check: CheckBox?=null
        var tv: TextView?=null

        super.onCreate(savedInstanceState)
        enableEdgeToEdge()
        setContentView(R.layout.activity_main)

        tv = findViewById(R.id.tv1)
        check = findViewById(R.id.check)



        check!!.setOnClickListener{
            if(check!!.isChecked)
                tv!!.text=("Checked")
            else
                tv!!.text=("UnChecked")

        }

    }
}

E:\android\android apps\MyApplication2\app\build.gradle.kts

android {
    compileSdk = 36

  defaultConfig {
        targetSdk = 36
    }

E:\android\android apps\MyApplication2\gradle\wrapper\gradle-wrapper.properties

#Tue Sep 09 12:55:09 IST 2025
distributionBase=GRADLE_USER_HOME
distributionPath=wrapper/dists
#distributionUrl=https\://services.gradle.org/distributions/gradle-8.7-bin.zip
#distributionUrl=https\://services.gradle.org/distributions/gradle-8.9-bin.zip
distributionUrl=https\://services.gradle.org/distributions/gradle-8.11.1-bin.zip

zipStoreBase=GRADLE_USER_HOME
zipStorePath=wrapper/dists

E:\android\android apps\MyApplication2\gradle\libs.versions.toml

[versions]
agp = "8.6.0"
kotlin = "1.9.0"
coreKtx = "1.10.1"
junit = "4.13.2"
junitVersion = "1.3.0"
espressoCore = "3.7.0"
appcompat = "1.7.1"
material = "1.12.0"
activity = "1.10.1"
constraintlayout = "2.2.1"

[libraries]
androidx-core-ktx = { group = "androidx.core", name = "core-ktx", version.ref = "coreKtx" }
junit = { group = "junit", name = "junit", version.ref = "junit" }
androidx-junit = { group = "androidx.test.ext", name = "junit", version.ref = "junitVersion" }
androidx-espresso-core = { group = "androidx.test.espresso", name = "espresso-core", version.ref = "espressoCore" }
androidx-appcompat = { group = "androidx.appcompat", name = "appcompat", version.ref = "appcompat" }
material = { group = "com.google.android.material", name = "material", version.ref = "material" }
androidx-activity = { group = "androidx.activity", name = "activity", version.ref = "activity" }
androidx-constraintlayout = { group = "androidx.constraintlayout", name = "constraintlayout", version.ref = "constraintlayout" }

[plugins]
android-application = { id = "com.android.application", version.ref = "agp" }
kotlin-android = { id = "org.jetbrains.kotlin.android", version.ref = "kotlin" }

Output:

SEEKBAR

E:\android\MyApplication\app\src\main\res\layout\activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity"
    android:orientation="vertical">

    <SeekBar
        android:id="@+id/seekBar1"
        android:layout_width="300dp"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_marginTop="26dp"
        android:max="10"/>
    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/seekBar1"
        android:layout_marginLeft="29dp"
        android:layout_marginTop="14dp" />

</LinearLayout>

E:\android\MyApplication\app\src\main\java\com\example\myapplication\MainActivity.kt

package com.example.myapplication

import android.os.Bundle
import android.widget.SeekBar
import android.widget.TextView
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity

class MainActivity : AppCompatActivity() {

    private lateinit var seekBar: SeekBar
    private lateinit var textView: TextView

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        // Enable edge-to-edge content
        enableEdgeToEdge()

        // Initialize views
        seekBar = findViewById(R.id.seekBar1)
        textView = findViewById(R.id.textView1)

        // Initialize the text view with the initial progress
        textView.text = "${seekBar.progress}/${seekBar.max}"
        var progress = 0
        // Set up the seek bar change listener
        seekBar.setOnSeekBarChangeListener(object : SeekBar.OnSeekBarChangeListener {

            override fun onProgressChanged(seekBar: SeekBar?, progresValue: Int, fromUser: Boolean) {
                //textView.text = "$progress/${seekBar?.max}"
                progress = progresValue
            }

            override fun onStartTrackingTouch(seekBar: SeekBar?) {
                // Optional: Do something when tracking starts
            }

            override fun onStopTrackingTouch(seekBar: SeekBar?) {
                // Optional: Do something when tracking stops
                textView.text = "$progress/${this@MainActivity.seekBar.max}"
            }
        })
    }
}

IMAGEVIEW

E:\android\MyApplication\app\src\main\res\layout\activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity"
    android:orientation="vertical">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Radio Button Example"
        android:textAllCaps="true"
        android:textStyle="italic"
        android:textSize="20sp"
        android:textColor="#309"
        android:padding="5dp"
        android:layout_margin="5dp"
        android:id="@+id/tv1"/>

    <ImageView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/iv"
        android:src="@mipmap/ic_launcher"></ImageView>


</LinearLayout>

E:\android\MyApplication\app\src\main\java\com\example\myapplication\MainActivity.kt

package com.example.myapplication

import android.annotation.SuppressLint
import android.os.Bundle
import android.widget.ImageView

import android.widget.Toast
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity

class MainActivity : AppCompatActivity() {

    var iv: ImageView?=null

    @SuppressLint("WrongConstant")
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        // Enable edge-to-edge content
        enableEdgeToEdge()
        iv=findViewById(R.id.iv)

        iv!!.setOnClickListener{
            Toast.makeText(applicationContext,"You seletd image",Toast.LENGTH_LONG).show()
        }


    }
}

IMAGE BUTTON

E:\android\MyApplication\app\src\main\res\layout\activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity"
    android:orientation="vertical">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Radio Button Example"
        android:textAllCaps="true"
        android:textStyle="italic"
        android:textSize="20sp"
        android:textColor="#309"
        android:padding="5dp"
        android:layout_margin="5dp"
        android:id="@+id/tv1"
        />

        <ImageButton
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/ib"
        android:src="@mipmap/ic_launcher"></ImageButton>

</LinearLayout>

E:\android\MyApplication\app\src\main\res\layout\activity_main.xml

package com.example.myapplication

import android.annotation.SuppressLint
import android.os.Bundle
import android.widget.ImageButton

import android.widget.Toast
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity

class MainActivity : AppCompatActivity() {


    var ib: ImageButton?=null

    @SuppressLint("WrongConstant")
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        // Enable edge-to-edge content
        enableEdgeToEdge()
        ib=findViewById(R.id.ib)

        ib!!.setOnClickListener{
            Toast.makeText(applicationContext,"You seletcd imagebutton",5000).show()
        }

    }
}

Output

INTENTS

E:\android\MyApplication\app\build.gradle.kts

    buildTypes {

    dataBinding{
        enable=true
        //enabled=true old version of android sdk Do it
    }

}

E:\android\MyApplication\app\src\main\AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">

    <application
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.MyApplication">
        <activity
            android:name=".Activity_third"
            android:exported="false" />
        <activity
            android:name=".Activity_second"
            android:exported="false" />
        <activity
            android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

E:\android\MyApplication\app\src\main\java\com\example\myapplication\MainActivity.kt

<?xml version="1.0" encoding="utf-8"?>
<layout>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="We are in First Page"
        />
    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/name"/>
    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/mobile"/>
    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Move to Second"
        android:id="@+id/bt1"
        />
</LinearLayout>
</layout>

E:\android\MyApplication\app\src\main\java\com\example\myapplication\MainActivity.kt

package com.example.myapplication

import android.annotation.SuppressLint
import android.content.Intent
import android.os.Bundle
import android.widget.Toast
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity
import androidx.databinding.DataBindingUtil
import com.example.myapplication.databinding.ActivityMainBinding

class MainActivity : AppCompatActivity() {
    var binding: ActivityMainBinding?=null

    @SuppressLint("WrongConstant")
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        // Enable edge-to-edge content
        enableEdgeToEdge()
        binding= DataBindingUtil.setContentView(this,R.layout.activity_main)

        binding?.bt1?.setOnClickListener{
            var intent= Intent(this@MainActivity,Activity_second::class.java)
            // intent.putExtra("key","values")
            intent.putExtra("name",binding?.name?.text.toString())
            intent.putExtra("mobile",binding?.mobile?.text.toString())
            startActivity(intent)
        }

    }
}

E:\android\MyApplication\app\src\main\res\layout\activity_second.xml

<?xml version="1.0" encoding="utf-8"?>
<layout>
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        tools:context=".Second">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="We are in Second Page" />

        <Button
            android:id="@+id/bt2"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="Move to Third" />
    </LinearLayout>

</layout>

E:\android\MyApplication\app\src\main\java\com\example\myapplication\Activity_second.kt

package com.example.myapplication

import android.content.Intent
import android.os.Bundle
import android.widget.Toast
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity
import androidx.core.view.ViewCompat
import androidx.core.view.WindowInsetsCompat
import androidx.databinding.DataBindingUtil
import com.example.myapplication.databinding.ActivitySecondBinding

class Activity_second : AppCompatActivity() {
    var binding: ActivitySecondBinding? = null

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        enableEdgeToEdge()
        setContentView(R.layout.activity_second)
        binding = DataBindingUtil.setContentView(this, R.layout.activity_second)
        var dataintent = intent
        var s1 = dataintent.getStringExtra("name")
        var s2 = dataintent.getStringExtra("mobile")
        Toast.makeText(this, "" + s1 + s2, Toast.LENGTH_LONG).show()
        binding?.bt2?.setOnClickListener {
            var intent = Intent(this, Activity_third::class.java)
            intent.putExtra("data", s1 + s2)
            startActivity(intent)
            // finish()
        }


    }
}

E:\android\MyApplication\app\src\main\res\layout\activity_third.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Activity_third">

</androidx.constraintlayout.widget.ConstraintLayout>

E:\android\MyApplication\app\src\main\java\com\example\myapplication\Activity_third.kt

package com.example.myapplication

import android.content.Intent
import android.os.Bundle
import android.widget.Toast
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity
import androidx.core.view.ViewCompat
import androidx.core.view.WindowInsetsCompat

class Activity_third : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        enableEdgeToEdge()
        setContentView(R.layout.activity_third)
//        ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main)) { v, insets ->
//            val systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars())
//            v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom)
//            insets
//        }
        var dataintent=intent
        var s1=dataintent.getStringExtra("data")
        Toast.makeText(this,""+s1, Toast.LENGTH_LONG).show()

    }

    override fun onBackPressed() {
        super.onBackPressed()
        var intent= Intent(this,MainActivity::class.java)
        startActivity(intent)
        finish() // Optionally finish this activity to remove it from the back stack
    }

}

Output

Server

Open CMD

C:\Users\AECN>ipconfig

Windows IP Configuration


Ethernet adapter Ethernet:

   Connection-specific DNS Suffix  . : bbrouter
   IPv6 Address. . . . . . . . . . . : 2001:4490:4c6d:3711:704b:cab5:304d:ceb7
   IPv6 Address. . . . . . . . . . . : 2001:4490:4c6d:b2a3:c3b6:301d:9faf:f6c
   Temporary IPv6 Address. . . . . . : 2001:4490:4c6d:3711:5932:79d:904b:fdfd
   Temporary IPv6 Address. . . . . . : 2001:4490:4c6d:b2a3:5932:79d:904b:fdfd
   Link-local IPv6 Address . . . . . : fe80::f83a:f49a:b92:4e5d%4
   IPv4 Address. . . . . . . . . . . : 192.168.1.27
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Default Gateway . . . . . . . . . : fe80::1%4
                                       192.168.1.1

Python 

python --version
python -m pip install django
python -m django --version
python -m django startproject aecpro

go to aecpro folder

add 

settings.py chnage this line

ALLOWED_HOSTS = ["0.0.0.0","*"]

after run this on cmd 

python manage.py runserver 0.0.0.0:8080

http://192.168.1.27:8080/

ADVANCED USER INTERFACE/predefined layout & data from Res

E:\android\MyApplication\app\src\main\AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">

    <application
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.MyApplication">
        <activity
            android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

E:\android\MyApplication\app\src\main\res\layout\activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<layout>
    <LinearLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".MainActivity"
        android:orientation="vertical">
    <ListView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/list"/>
    </LinearLayout>

</layout>

E:\android\MyApplication\app\src\main\java\com\example\myapplication\MainActivity.kt

package com.example.myapplication

import android.annotation.SuppressLint
import android.content.Intent
import android.net.Uri
import android.os.Bundle
import android.provider.MediaStore
import android.widget.ArrayAdapter
import android.widget.Toast
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity
import androidx.databinding.DataBindingUtil
import com.example.myapplication.databinding.ActivityMainBinding

class MainActivity : AppCompatActivity() {
    var binding: ActivityMainBinding? = null

    var Course = arrayOf(
        "Android", "Java", "CoreJava", "Adv Java",
        "PHP", "Python", "Core Java", "Adv Java", "Android", "Java",
        "CoreJava", "Adv Java", "PHP", "Python", "Core Java", "Adv Java",
        "Android", "Java", "CoreJava", "Adv Java", "PHP", "Python", "Core Java", "Adv Java"
    )


    @SuppressLint("WrongConstant")
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        // Enable edge-to-edge content
        enableEdgeToEdge()
        binding = DataBindingUtil.setContentView(this, R.layout.activity_main)

// predefined layout & data from kotlin
//        var courseadapter= ArrayAdapter(this@MainActivity,android.R.layout.simple_list_item_1  ,Course)
//        binding?.list?.adapter=courseadapter

// predefined layout & data from Res
        var xyz = resources.getStringArray(R.array.xyz)
        var courseadapter = ArrayAdapter(
            this@MainActivity,
            android.R.layout.simple_list_item_1,
            resources.getStringArray(R.array.xyz)
        )
        binding?.list?.adapter = courseadapter

        // custom layout & data from kotlin
        //var courseadapter=
//        ArrayAdapter(this@MainActivity,R.layout.custom, Course)
//        //binding?.list?.adapter=courseadapter
//        binding?.list?.setOnItemClickListener { parent, view, position, id ->
//            Toast.makeText(this,""+position,Toast.LENGTH_LONG).show()
//        }


    }
}

E:\android\MyApplication\app\src\main\res\values\strings.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="app_name">List</string>
    <string-array name="xyz">
        <item>ATK</item>
        <item>NLR</item>
        <item>KDP</item>
        <item>ANTHASAGARAM</item>
        <item>Chilakalamarri</item>
        <item>Mangupalli</item>
        <item>Gudugunta</item>
        <item>Yeguvapalli</item>
        <item>HYD</item>
        <item>CHE</item>
        <item>KOL</item>
        <item>ATK</item>
        <item>NLR</item>
        <item>KDP</item>
        <item>ANTHASAGARAM</item>
        <item>Chilakalamarri</item>
        <item>Mangupalli</item>
        <item>Gudugunta</item>
        <item>Yeguvapalli</item>
        <item>HYD</item>
        <item>CHE</item>
        <item>KOL</item>
        <item>ATK</item>
        <item>NLR</item>
        <item>KDP</item>
        <item>ANTHASAGARAM</item>
        <item>Chilakalamarri</item>
        <item>Mangupalli</item>
        <item>Gudugunta</item>
        <item>Yeguvapalli</item>
        <item>HYD</item>
        <item>CHE</item>
        <item>KOL</item>
        <item>ATK</item>
        <item>NLR</item>
        <item>KDP</item>
        <item>ANTHASAGARAM</item>
        <item>Chilakalamarri</item>
        <item>Mangupalli</item>
        <item>Gudugunta</item>
        <item>Yeguvapalli</item>
        <item>HYD</item>
        <item>CHE</item>
        <item>KOL</item>
        <item>ATK</item>
        <item>NLR</item>
        <item>KDP</item>
        <item>ANTHASAGARAM</item>
        <item>Chilakalamarri</item>
        <item>Mangupalli</item>
        <item>Gudugunta</item>
        <item>Yeguvapalli</item>
        <item>HYD</item>
        <item>CHE</item>
        <item>KOL</item>

    </string-array>
</resources>

ADVANCED USER INTERFACE/custom layout & data from kotlin

E:\android\MyApplication\app\src\main\AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">

    <application
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.MyApplication">
        <activity
            android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

E:\android\MyApplication\app\src\main\java\com\example\myapplication\MainActivity.kt

package com.example.myapplication

import android.annotation.SuppressLint
import android.content.Intent
import android.net.Uri
import android.os.Bundle
import android.provider.MediaStore
import android.widget.ArrayAdapter
import android.widget.Toast
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity
import androidx.databinding.DataBindingUtil
import com.example.myapplication.databinding.ActivityMainBinding

class MainActivity : AppCompatActivity() {
    var binding: ActivityMainBinding? = null

    var Course = arrayOf(
        "Android", "Java", "CoreJava", "Adv Java",
        "PHP", "Python", "Core Java", "Adv Java", "Android", "Java",
        "CoreJava", "Adv Java", "PHP", "Python", "Core Java", "Adv Java",
        "Android", "Java", "CoreJava", "Adv Java", "PHP", "Python", "Core Java", "Adv Java"
    )


    @SuppressLint("WrongConstant")
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        // Enable edge-to-edge content
        enableEdgeToEdge()
        binding = DataBindingUtil.setContentView(this, R.layout.activity_main)

// predefined layout & data from kotlin
//        var courseadapter= ArrayAdapter(this@MainActivity,android.R.layout.simple_list_item_1  ,Course)
//        binding?.list?.adapter=courseadapter

// predefined layout & data from Res
//        var xyz = resources.getStringArray(R.array.xyz)
//        var courseadapter = ArrayAdapter(
//            this@MainActivity,
//            android.R.layout.simple_list_item_1,
//            resources.getStringArray(R.array.xyz)
//        )
//        binding?.list?.adapter = courseadapter

        // custom layout & data from kotlin
        var courseadapter=ArrayAdapter(this@MainActivity,R.layout.custom, Course)
        binding?.list?.adapter=courseadapter

        binding?.list?.setOnItemClickListener { parent, view, position, id ->
            // Get the clicked item value from the adapter
            val selectedItem = parent.getItemAtPosition(position).toString()
            Toast.makeText(this@MainActivity, "Position: $position, Value: $selectedItem", Toast.LENGTH_LONG).show()
        }

    }
}

E:\android\MyApplication\app\src\main\res\layout\activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<layout>
    <LinearLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".MainActivity"
        android:orientation="vertical">
    <ListView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/list"/>
    </LinearLayout>

</layout>

E:\android\MyApplication\app\src\main\res\layout\custom.xml

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:textStyle="bold"
    android:textAllCaps="true"
    android:textColor="#FF5722"
    android:textSize="20sp"
    android:layout_margin="10dp"
    android:padding="10dp">
</TextView>

ADVANCED USER INTERFACE

predefined layout/ArrayAdapter - > android.R.layout.simple_list_item_1

E:\android\MyApplication\app\src\main\AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">

    <application
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.MyApplication">
        <activity
            android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

E:\android\MyApplication\app\src\main\res\layout\activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<layout>
    <LinearLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".MainActivity"
        android:orientation="vertical">
    <ListView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/list"/>
    </LinearLayout>

</layout>

E:\android\MyApplication\app\src\main\java\com\example\myapplication\MainActivity.kt

package com.example.myapplication

import android.annotation.SuppressLint
import android.content.Intent
import android.net.Uri
import android.os.Bundle
import android.provider.MediaStore
import android.widget.ArrayAdapter
import android.widget.Toast
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity
import androidx.databinding.DataBindingUtil
import com.example.myapplication.databinding.ActivityMainBinding

class MainActivity : AppCompatActivity() {
    var binding: ActivityMainBinding? = null

    var Course = arrayOf(
        "Android", "Java", "CoreJava", "Adv Java",
        "PHP", "Python", "Core Java", "Adv Java", "Android", "Java",
        "CoreJava", "Adv Java", "PHP", "Python", "Core Java", "Adv Java",
        "Android", "Java", "CoreJava", "Adv Java", "PHP", "Python", "Core Java", "Adv Java"
    )


    @SuppressLint("WrongConstant")
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        // Enable edge-to-edge content
        enableEdgeToEdge()
        binding = DataBindingUtil.setContentView(this, R.layout.activity_main)

// predefined layout & data from kotlin
        var courseadapter =
            ArrayAdapter(this@MainActivity, android.R.layout.simple_list_item_1, Course)
        binding?.list?.adapter = courseadapter


    }
}

 

Output

ADVANCED USER INTERFACE/predefined GRIDVIEW EXAMPLE /data from kotlin

using Predfined 

Case 01(using Predfined):

E:\android\MyApplication\app\src\main\res\layout\activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<layout>
    <RelativeLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".MainActivity">
        <GridView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/grid"
            android:layout_margin="10dp"
            android:numColumns="auto_fit"/>
    </RelativeLayout>
</layout>

E:\android\MyApplication\app\src\main\java\com\example\myapplication\MainActivity.kt

package com.example.myapplication

import android.annotation.SuppressLint
import android.content.Intent
import android.net.Uri
import android.os.Bundle
import android.provider.MediaStore
import android.widget.ArrayAdapter
import android.widget.Toast
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity
import androidx.databinding.DataBindingUtil
import com.example.myapplication.databinding.ActivityMainBinding

class MainActivity : AppCompatActivity() {
    var binding: ActivityMainBinding? = null

    var Course = arrayOf(
        "Android", "Java", "CoreJava", "Adv Java",
        "PHP", "Python", "Core Java", "Adv Java", "Android", "Java",
        "CoreJava", "Adv Java", "PHP", "Python", "Core Java", "Adv Java",
        "Android", "Java", "CoreJava", "Adv Java", "PHP", "Python", "Core Java", "Adv Java"
    )


    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        // Enable edge-to-edge content
        enableEdgeToEdge()
        binding = DataBindingUtil.setContentView(this, R.layout.activity_main)

        var gridadaprer= ArrayAdapter(this,android.R.layout.simple_list_item_1, Course)
        binding?.grid?.adapter=gridadaprer

        // Handle item clicks and show both position and value
        binding?.grid?.setOnItemClickListener { parent, view, position, id ->
            val selectedItem = parent.getItemAtPosition(position) as String
            Toast.makeText(this, "Position: $position\nValue: $selectedItem", Toast.LENGTH_LONG).show()
        }


    }
}

Case 02(User Defined):

E:\android\MyApplication\app\src\main\res\layout\activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<layout>
    <RelativeLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".MainActivity">
        <GridView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/grid"
            android:layout_margin="10dp"
            android:numColumns="auto_fit"/>
    </RelativeLayout>
</layout>

E:\android\MyApplication\app\src\main\res\layout\custom.xml

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/customTextView"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:gravity="center"
    android:padding="16dp"
    android:textSize="18sp"
    android:textStyle="bold"
    android:textAllCaps="true"
    android:textColor="#FF5722"
    android:layout_margin="10dp">

</TextView>

E:\android\MyApplication\app\src\main\java\com\example\myapplication\MainActivity.kt

package com.example.myapplication

import android.annotation.SuppressLint
import android.content.Intent
import android.net.Uri
import android.os.Bundle
import android.provider.MediaStore
import android.widget.ArrayAdapter
import android.widget.Toast
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity
import androidx.databinding.DataBindingUtil
import com.example.myapplication.databinding.ActivityMainBinding

class MainActivity : AppCompatActivity() {
    var binding: ActivityMainBinding? = null

    var Course = arrayOf(
        "Android", "Java", "CoreJava", "Adv Java",
        "PHP", "Python", "Core Java", "Adv Java", "Android", "Java",
        "CoreJava", "Adv Java", "PHP", "Python", "Core Java", "Adv Java",
        "Android", "Java", "CoreJava", "Adv Java", "PHP", "Python", "Core Java", "Adv Java",
        "CoreJava", "Adv Java", "PHP", "Python", "Core Java", "Adv Java",
        "Android", "Java", "CoreJava", "Adv Java", "PHP", "Python", "Core Java", "Adv Java",
        "CoreJava", "Adv Java", "PHP", "Python", "Core Java", "Adv Java",
        "Android", "Java", "CoreJava", "Adv Java", "PHP", "Python", "Core Java", "Adv Java"

    )


    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        // Enable edge-to-edge content
        enableEdgeToEdge()
        binding = DataBindingUtil.setContentView(this, R.layout.activity_main)

        var gridadaprer= ArrayAdapter(this,R.layout.custom, Course)
        binding?.grid?.adapter=gridadaprer

        // Handle item clicks and show both position and value
        binding?.grid?.setOnItemClickListener { parent, view, position, id ->
            val selectedItem = parent.getItemAtPosition(position) as String
            Toast.makeText(this, "Position: $position\nValue: $selectedItem", Toast.LENGTH_LONG).show()
        }


    }
}

AUTOCOMPLETETEXTVIEW EXAMPLE

E:\android\MyApplication\app\src\main\res\layout\activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<layout>
    <RelativeLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".MainActivity">

        <GridView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/grid"
            android:layout_margin="10dp"
            android:numColumns="auto_fit"/>

        <Spinner
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/spin"
            android:layout_below="@id/grid"
            android:layout_margin="10dp"/>


        <AutoCompleteTextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/auto"
            android:layout_below="@id/spin"
            android:completionThreshold="1"
            android:layout_margin="10dp"/>
    </RelativeLayout>
</layout>

E:\android\MyApplication\app\src\main\java\com\example\myapplication\MainActivity.kt

package com.example.myapplication

import android.annotation.SuppressLint
import android.content.Intent
import android.net.Uri
import android.os.Bundle
import android.provider.MediaStore
import android.widget.ArrayAdapter
import android.widget.Toast
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity
import androidx.databinding.DataBindingUtil
import com.example.myapplication.databinding.ActivityMainBinding

class MainActivity : AppCompatActivity() {
    var binding: ActivityMainBinding? = null


    var course=arrayOf("Android", "Java","CoreJava","Core Java","advjava","adv Java",
        "python","androidjava","javaandroid")



    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        // Enable edge-to-edge content
        enableEdgeToEdge()
        binding = DataBindingUtil.setContentView(this, R.layout.activity_main)

        var autoadapter= ArrayAdapter(this,android.R.layout.simple_list_item_1, course)
        binding?.auto?.setAdapter(autoadapter)

    }
}

Adding Text to Images
👉 Use cv2.putText()

import cv2
import matplotlib.pyplot as plt

# Load image
img1 = cv2.imread("images/parrot.jpg")
output = img1.copy()

# Put text on image
cv2.putText(output, "Hello OpenCV!", (50, 100),
            cv2.FONT_HERSHEY_SIMPLEX, 2, (0, 255, 0), 3)

# Convert BGR → RGB for matplotlib
output_rgb = cv2.cvtColor(output, cv2.COLOR_BGR2RGB)

# Display safely in notebook
plt.imshow(output_rgb)
plt.axis('on')
plt.title("Text on Image")
plt.show()

Changing the Shape of Images

resized = cv2.resize(img1, (300, 300))
cropped = img1[50:200, 100:300]   # crop region
flipped = cv2.flip(img1, 1)       # horizontal flip

6. Effecting Image Thresholding

👉 Binary thresholding and adaptive thresholding.

import numpy as np
from skimage.transform import (hough_line, hough_line_peaks, hough_circle, hough_circle_peaks)

from skimage.draw import circle_perimeter
from skimage.feature import canny
from skimage.data import astronaut
from skimage.io import imread, imsave
from skimage.color import rgb2gray, gray2rgb, label2rgb
from skimage import img_as_float
from skimage.morphology import skeletonize
from skimage import data, img_as_float
import matplotlib.pyplot as plt
from matplotlib import cm
from skimage.filters import sobel, threshold_otsu
from skimage.feature import canny
from skimage.segmentation import felzenszwalb, slic, quickshift, watershed
from skimage.segmentation import mark_boundaries, find_boundaries
# Load and preprocess image
image = rgb2gray(imread('images/horse.jpg'))
thresh = threshold_otsu(image)
binary = image > thresh

# Plotting
fig, axes = plt.subplots(nrows=2, ncols=2, figsize=(20, 15))
ax = axes.ravel()

ax[0].imshow(image, cmap=plt.cm.gray)
ax[0].set_title('Original', size=20)
ax[0].axis('off')

ax[1].hist(image.ravel(), bins=256, density=True)  # <-- use density instead of normed
ax[1].set_title('Histogram', size=20)
ax[1].axvline(thresh, color='r')

ax[2].imshow(binary, cmap=plt.cm.gray)
ax[2].set_title('Thresholded (Otsu)', size=20)
ax[2].axis('off')

ax[3].axis('off')

plt.tight_layout()
plt.show()

Performing Histogram Equalization.

import numpy as np
import matplotlib.pyplot as plt
from skimage.io import imread
from skimage.color import rgb2gray
from skimage.filters.rank import enhance_contrast
from skimage.morphology import disk
from skimage import exposure, img_as_ubyte

# Helper function
def plot_gray_image(ax, image, title):
    ax.imshow(image, cmap='gray')
    ax.set_title(title)
    ax.axis('off')
    ax.set_adjustable('box')  # valid value

# Load image and convert to grayscale
image = rgb2gray(imread('images/squirrel.jpg'))

# Add noise
sigma = 0.05
noisy_image = np.clip(image + sigma * np.random.standard_normal(image.shape), 0, 1)

# Convert to uint8 for rank filters
noisy_uint8 = img_as_ubyte(noisy_image)

# Local morphological contrast enhancement
enhanced_image = enhance_contrast(noisy_uint8, disk(5))

# Adaptive histogram equalization (works with float)
equalized_image = exposure.equalize_adapthist(noisy_image)

# Plot results
fig, axes = plt.subplots(1, 3, figsize=(18, 7), sharex=True, sharey=True)
axes1, axes2, axes3 = axes.ravel()

plot_gray_image(axes1, noisy_image, 'Original')
plot_gray_image(axes2, enhanced_image / 255.0, 'Local morphological contrast enhancement')  # normalize for display
plot_gray_image(axes3, equalized_image, 'Adaptive Histogram equalization')

plt.show()

RADIO GROUP AND RADIO BUTTON

E:\android\MyApplication\app\src\main\res\layout\activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity"
    android:orientation="vertical">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textColor="#FF5722"
        android:textSize="30sp"
        android:textStyle="bold"
        android:textAllCaps="true"
        android:padding="10dp"
        android:layout_margin="10dp"
        android:gravity="center"
        android:layout_gravity="center"
        android:id="@+id/tv1"
        />


    <RadioGroup
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:id="@+id/rg">
        <RadioButton
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/r1"
            android:text="Male"></RadioButton>
        <RadioButton
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/r2"
            android:text="Female"></RadioButton>
    </RadioGroup>

</LinearLayout>

E:\android\MyApplication\app\src\main\java\com\example\myapplication\MainActivity.kt

package com.example.myapplication

import android.os.Bundle
import android.widget.RadioButton
import android.widget.RadioGroup
import android.widget.TextView
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity

class MainActivity : AppCompatActivity() {

    private lateinit var tv: TextView
    private lateinit var radiogroup: RadioGroup
    private lateinit var r1: RadioButton
    private lateinit var r2: RadioButton

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        // Enable edge-to-edge content
        enableEdgeToEdge()

        // Find views by ID
        tv = findViewById(R.id.tv1)
        radiogroup = findViewById(R.id.rg)
        r1 = findViewById(R.id.r1)
        r2 = findViewById(R.id.r2)

        // Set a listener for the RadioGroup
        radiogroup.setOnCheckedChangeListener { group, checkedId ->
            when (checkedId) {
                R.id.r1 -> tv.text = "MALE"
                R.id.r2 -> tv.text = "FEMALE"
            }
        }
    }
}

Output:

E:\android\MyApplication\app\src\main\res\layout\activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity"
    android:orientation="vertical">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textColor="#FF5722"
        android:textSize="30sp"
        android:textStyle="bold"
        android:textAllCaps="true"
        android:padding="10dp"
        android:layout_margin="10dp"
        android:gravity="center"
        android:layout_gravity="center"
        android:id="@+id/tv1"
        />
    <Switch
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Switch"
        android:textColor="#FF5722"
        android:textSize="30sp"
        android:textStyle="bold"
        android:textAllCaps="true"
        android:padding="10dp"
        android:layout_margin="10dp"
        android:gravity="center"
        android:layout_gravity="center"
        android:id="@+id/switch1"></Switch>

</LinearLayout>

E:\android\MyApplication\app\src\main\java\com\example\myapplication\MainActivity.kt

package com.example.myapplication
import android.os.Bundle
import android.widget.Switch
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity
import android.widget.TextView


class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)


        var tv: TextView?=null
        var swit: Switch?=null

        enableEdgeToEdge()
        setContentView(R.layout.activity_main)

        tv = findViewById(R.id.tv1)
        swit=findViewById(R.id.switch1)

        swit!!.setOnClickListener{
            if(swit!!.isChecked)
                tv!!.text=("SON")
            else
                tv!!.text=("SOFF")
        }

    }
}

Output:

RATING BAR

E:\android\MyApplication\app\src\main\res\layout\activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity"
    android:orientation="vertical">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Radio Button Example"
        android:textAllCaps="true"
        android:textStyle="italic"
        android:textSize="20sp"
        android:textColor="#309"
        android:padding="5dp"
        android:layout_margin="5dp"
        android:id="@+id/tv1"/>

    <RatingBar
        android:id="@+id/ratingBar"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:stepSize="1"/>

</LinearLayout>

E:\android\MyApplication\app\src\main\java\com\example\myapplication\MainActivity.kt

package com.example.myapplication

import android.annotation.SuppressLint
import android.os.Bundle
import android.widget.RatingBar
import android.widget.Toast
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity

class MainActivity : AppCompatActivity() {

    var ratingbar: RatingBar?=null
    @SuppressLint("WrongConstant")
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        // Enable edge-to-edge content
        enableEdgeToEdge()
        ratingbar = findViewById(R.id.ratingBar)
        ratingbar!!.setOnRatingBarChangeListener { ratingBar, fl, b ->
            Toast.makeText(applicationContext,"you seleted"+fl,Toast.LENGTH_LONG).show()
        }

    }
}

Output

RECYCLERVIEW

RecyclerView is a powerful and flexible UI component introduced in Android's support library to efficiently display large datasets in a scrollable list or grid format. It's an improved version of the older ListView and GridView components, providing better performance, more flexibility, and easier customization. Here's an explanation of RecyclerView in Android:

• Purpose:

• RecyclerView is designed to efficiently display large datasets in a scrollable list or grid format.

• It efficiently manages the memory usage by recycling views as they move off-screen, reducing the need for creating and destroying views dynamically.

• RecyclerView provides a flexible architecture for implementing various layout managers, item decorations, and item animations.

E:\android\MyApplication\app\build.gradle.kts

android {
    dataBinding{
        enable=true
        //enabled=true old version of android sdk Do it
    }

}

E:\android\MyApplication\app\src\main\AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">

    <application
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.MyApplication">
        <activity
            android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

E:\android\MyApplication\app\src\main\res\layout\activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<layout>
    <RelativeLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".MainActivity">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Recycler view example"
            android:id="@+id/tv1"
            />
        <androidx.recyclerview.widget.RecyclerView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/rec"
            android:layout_below="@id/tv1"
            android:layout_margin="10dp"/>
    </RelativeLayout>

</layout>

E:\android\MyApplication\app\src\main\java\com\example\myapplication\MainActivity.kt

package com.example.myapplication

import android.annotation.SuppressLint
import android.content.Intent
import android.net.Uri
import android.os.Bundle
import android.provider.MediaStore
import android.widget.ArrayAdapter
import android.widget.Toast
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity
import androidx.databinding.DataBindingUtil
import androidx.recyclerview.widget.LinearLayoutManager
import com.example.myapplication.databinding.ActivityMainBinding

class MainActivity : AppCompatActivity() {
    var binding: ActivityMainBinding? = null

//    var Names=arrayOf("AAA","BBB","CCC")
//    var Mobile=arrayOf("5253","87567","7565")
//    var Emails=arrayOf("aaa@gmail.com","bbb@yamil.com","ccc@hotmail.com")
//    var Profile=arrayOf(R.mipmap.ic_launcher,R.mipmap.ic_launcher_round,R.mipmap.ic_launcher)
var Names = arrayOf(
    "AAA","BBB","CCC","DDD","EEE","FFF","GGG","HHH","III","JJJ",
    "KKK","LLL","MMM","NNN","OOO","PPP","QQQ","RRR","SSS","TTT"
)

    var Mobile = arrayOf(
        "5253","87567","7565","1234","9876","5432","6789","3456","7890","2345",
        "4567","6781","2346","9872","5643","6784","3457","9873","4568","7891"
    )

    var Emails = arrayOf(
        "aaa@gmail.com","bbb@yamil.com","ccc@hotmail.com","ddd@gmail.com","eee@yahoo.com",
        "fff@hotmail.com","ggg@gmail.com","hhh@yahoo.com","iii@hotmail.com","jjj@gmail.com",
        "kkk@yahoo.com","lll@hotmail.com","mmm@gmail.com","nnn@yahoo.com","ooo@hotmail.com",
        "ppp@gmail.com","qqq@yahoo.com","rrr@hotmail.com","sss@gmail.com","ttt@yahoo.com"
    )

    var Profile = arrayOf(
        R.mipmap.ic_launcher, R.mipmap.ic_launcher_round, R.mipmap.ic_launcher,
        R.mipmap.ic_launcher_round, R.mipmap.ic_launcher, R.mipmap.ic_launcher_round,
        R.mipmap.ic_launcher, R.mipmap.ic_launcher_round, R.mipmap.ic_launcher, R.mipmap.ic_launcher_round,
        R.mipmap.ic_launcher, R.mipmap.ic_launcher_round, R.mipmap.ic_launcher, R.mipmap.ic_launcher_round,
        R.mipmap.ic_launcher, R.mipmap.ic_launcher_round, R.mipmap.ic_launcher, R.mipmap.ic_launcher_round,
        R.mipmap.ic_launcher, R.mipmap.ic_launcher_round
    )


    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        // Enable edge-to-edge content
        enableEdgeToEdge()
        binding = DataBindingUtil.setContentView(this, R.layout.activity_main)

        var linearlayoutmanager= LinearLayoutManager(this@MainActivity,LinearLayoutManager.VERTICAL, false)
        binding?.rec?.layoutManager=linearlayoutmanager
        var customAdapter=CustomAdapter(this@MainActivity, Names,Mobile, Emails, Profile)
        binding?.rec?.adapter=customAdapter

    }
}

E:\android\MyApplication\app\src\main\res\layout\custom.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal">
    <ImageView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/iv"
        android:layout_margin="5dp"/>
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/linear"
        android:orientation="vertical">
        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/name"
            android:layout_margin="5dp"/>
        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/mobile"
            android:layout_margin="5dp"/>
        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/email"
            android:layout_margin="5dp"/>
    </LinearLayout>
</LinearLayout>

E:\android\MyApplication\app\src\main\java\com\example\myapplication\CustomAdapter.kt

package com.example.myapplication
import android.widget.Toast
import android.content.Context
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.ImageView
import android.widget.LinearLayout
import android.widget.TextView
import androidx.recyclerview.widget.RecyclerView

class CustomAdapter(mainActivity: MainActivity, names: Array<String>, mobile: Array<String>, emails: Array<String>, profile: Array<Int>) : RecyclerView.Adapter<CustomAdapter.MyViewHolder>() {
    var adpnames: Array<String>
    var adpmobile: Array<String>
    var adpemail: Array<String>
    var adpprofile: Array<Int>
    var adpContext: Context

    init {
        adpnames=names
        adpemail=emails
        adpmobile=mobile
        adpprofile=profile
        adpContext=mainActivity
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int):CustomAdapter.MyViewHolder {
        var view=LayoutInflater.from(parent.context).inflate(R.layout.custom,parent,false)
        return MyViewHolder(view)
    }

    override fun onBindViewHolder(holder: CustomAdapter.MyViewHolder,position: Int) {
        holder.name?.text=adpnames[holder.adapterPosition]
        holder.email?.text=adpemail[holder.adapterPosition]
        holder.mobile?.text=adpmobile[holder.adapterPosition]
        holder.profile?.setImageResource(adpprofile[holder.adapterPosition]
        )

        // When the profile image is clicked
        holder?.profile?.setOnClickListener {
            val info = "Name: ${adpnames[position]}\n" +
                    "Email: ${adpemail[position]}\n" +
                    "Mobile: ${adpmobile[position]}\n" +
                    "Profile ID: ${adpprofile[position]}"
            Toast.makeText(adpContext, info, Toast.LENGTH_LONG).show()
        }

        // When the whole item is clicked, show all information
        holder?.linearLayout?.setOnClickListener {
            val info = "Name: ${adpnames[position]}\n" +
                    "Email: ${adpemail[position]}\n" +
                    "Mobile: ${adpmobile[position]}\n" +
                    "Profile ID: ${adpprofile[position]}"
            Toast.makeText(adpContext, info, Toast.LENGTH_LONG).show()
        }

    }
    override fun getItemCount(): Int {
        return adpnames.size
    }
    inner class MyViewHolder (itemview:
                              View):RecyclerView.ViewHolder(itemview) {
        var name: TextView? = null
        var mobile: TextView? = null
        var email: TextView? = null
        var profile: ImageView? = null
        var linearLayout: LinearLayout? = null

        init {
            name = itemview.findViewById(R.id.name)
            mobile = itemview.findViewById(R.id.mobile)
            email = itemview.findViewById(R.id.email)
            profile = itemview.findViewById(R.id.iv)
            linearLayout = itemview.findViewById(R.id.linear)
        }
    }

}

Output

RECYCLERVIEW dynamic Maps

E:\android\MyApplication\app\build.gradle.kts

android {
    dataBinding{
        enable=true
        //enabled=true old version of android sdk Do it
    }

}

dependencies {
    implementation("org.osmdroid:osmdroid-android:6.1.14")
    implementation("androidx.preference:preference-ktx:1.2.1")
}

E:\android\MyApplication\app\src\main\AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">

    <uses-permission android:name="android.permission.INTERNET"/>
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>

    <application
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.MyApplication">
        <activity
            android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

E:\android\MyApplication\app\src\main\res\values\strings.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="app_name">List</string>
    <string-array name="xyz">
        <item>ATK</item>
        <item>NLR</item>
        <item>KDP</item>
        <item>ANTHASAGARAM</item>
        <item>Chilakalamarri</item>
        <item>Mangupalli</item>
        <item>Gudugunta</item>
        <item>Yeguvapalli</item>
        <item>HYD</item>
        <item>CHE</item>
        <item>KOL</item>
        <item>ATK</item>
        <item>NLR</item>
        <item>KDP</item>
        <item>ANTHASAGARAM</item>
        <item>Chilakalamarri</item>
        <item>Mangupalli</item>
        <item>Gudugunta</item>
        <item>Yeguvapalli</item>
        <item>HYD</item>
        <item>CHE</item>
        <item>KOL</item>
        <item>ATK</item>
        <item>NLR</item>
        <item>KDP</item>
        <item>ANTHASAGARAM</item>
        <item>Chilakalamarri</item>
        <item>Mangupalli</item>
        <item>Gudugunta</item>
        <item>Yeguvapalli</item>
        <item>HYD</item>
        <item>CHE</item>
        <item>KOL</item>
        <item>ATK</item>
        <item>NLR</item>
        <item>KDP</item>
        <item>ANTHASAGARAM</item>
        <item>Chilakalamarri</item>
        <item>Mangupalli</item>
        <item>Gudugunta</item>
        <item>Yeguvapalli</item>
        <item>HYD</item>
        <item>CHE</item>
        <item>KOL</item>
        <item>ATK</item>
        <item>NLR</item>
        <item>KDP</item>
        <item>ANTHASAGARAM</item>
        <item>Chilakalamarri</item>
        <item>Mangupalli</item>
        <item>Gudugunta</item>
        <item>Yeguvapalli</item>
        <item>HYD</item>
        <item>CHE</item>
        <item>KOL</item>

    </string-array>
<string-array name="tile_sources">
    <item>OSM Standard</item>
    <item>USGS Topo</item>
    <item>Watercolor</item>
</string-array>
</resources>

E:\android\MyApplication\app\src\main\res\layout\activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<layout>
    <RelativeLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".MainActivity">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Recycler view example"
            android:id="@+id/tv1"
            />
        <androidx.recyclerview.widget.RecyclerView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/rec"
            android:layout_below="@id/tv1"
            android:layout_margin="10dp"/>


    </RelativeLayout>

</layout> 

E:\android\MyApplication\app\src\main\res\layout\custom.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal">
    <ImageView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/iv"
        android:layout_margin="5dp"/>
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/linear"
        android:orientation="vertical">
        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/name"
            android:layout_margin="5dp"/>
        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/mobile"
            android:layout_margin="5dp"/>
        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/email"
            android:layout_margin="5dp"/>

        <!-- Spinner to switch tile sources -->
        <Spinner
            android:id="@+id/spinnerTile"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:entries="@array/tile_sources"
            android:layout_margin="5dp"/>

        <org.osmdroid.views.MapView
            android:id="@+id/map"
            android:layout_width="match_parent"
            android:layout_height="200dp"/>

    </LinearLayout>
</LinearLayout>

E:\android\MyApplication\app\src\main\java\com\example\myapplication\MainActivity.kt

package com.example.myapplication

import android.annotation.SuppressLint
import android.content.Intent
import android.net.Uri
import android.os.Bundle
import android.provider.MediaStore
import android.widget.ArrayAdapter
import android.widget.Toast
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity
import androidx.databinding.DataBindingUtil
import androidx.recyclerview.widget.LinearLayoutManager
import com.example.myapplication.databinding.ActivityMainBinding

class MainActivity : AppCompatActivity() {
    var binding: ActivityMainBinding? = null

//    var Names=arrayOf("AAA","BBB","CCC")
//    var Mobile=arrayOf("5253","87567","7565")
//    var Emails=arrayOf("aaa@gmail.com","bbb@yamil.com","ccc@hotmail.com")
//    var Profile=arrayOf(R.mipmap.ic_launcher,R.mipmap.ic_launcher_round,R.mipmap.ic_launcher)
var Names = arrayOf(
    "AAA","BBB","CCC","DDD","EEE","FFF","GGG","HHH","III","JJJ",
    "KKK","LLL","MMM","NNN","OOO","PPP","QQQ","RRR","SSS","TTT"
)

    var Mobile = arrayOf(
        "5253","87567","7565","1234","9876","5432","6789","3456","7890","2345",
        "4567","6781","2346","9872","5643","6784","3457","9873","4568","7891"
    )

    var Emails = arrayOf(
        "aaa@gmail.com","bbb@yamil.com","ccc@hotmail.com","ddd@gmail.com","eee@yahoo.com",
        "fff@hotmail.com","ggg@gmail.com","hhh@yahoo.com","iii@hotmail.com","jjj@gmail.com",
        "kkk@yahoo.com","lll@hotmail.com","mmm@gmail.com","nnn@yahoo.com","ooo@hotmail.com",
        "ppp@gmail.com","qqq@yahoo.com","rrr@hotmail.com","sss@gmail.com","ttt@yahoo.com"
    )

    var Profile = arrayOf(
        R.mipmap.ic_launcher, R.mipmap.ic_launcher_round, R.mipmap.ic_launcher,
        R.mipmap.ic_launcher_round, R.mipmap.ic_launcher, R.mipmap.ic_launcher_round,
        R.mipmap.ic_launcher, R.mipmap.ic_launcher_round, R.mipmap.ic_launcher, R.mipmap.ic_launcher_round,
        R.mipmap.ic_launcher, R.mipmap.ic_launcher_round, R.mipmap.ic_launcher, R.mipmap.ic_launcher_round,
        R.mipmap.ic_launcher, R.mipmap.ic_launcher_round, R.mipmap.ic_launcher, R.mipmap.ic_launcher_round,
        R.mipmap.ic_launcher, R.mipmap.ic_launcher_round
    )


    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        // Enable edge-to-edge content
        enableEdgeToEdge()
        binding = DataBindingUtil.setContentView(this, R.layout.activity_main)

        var linearlayoutmanager= LinearLayoutManager(this@MainActivity,LinearLayoutManager.VERTICAL, false)
        binding?.rec?.layoutManager=linearlayoutmanager
        var customAdapter=CustomAdapter(this@MainActivity, Names,Mobile, Emails, Profile)
        binding?.rec?.adapter=customAdapter

    }
}

E:\android\MyApplication\app\src\main\java\com\example\myapplication\CustomAdapter.kt

package com.example.myapplication

import android.content.Context
import android.graphics.Color
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.*
import androidx.recyclerview.widget.RecyclerView
import org.osmdroid.config.Configuration
import org.osmdroid.tileprovider.tilesource.TileSourceFactory
import org.osmdroid.tileprovider.tilesource.XYTileSource
import org.osmdroid.util.GeoPoint
import org.osmdroid.views.MapView
import org.osmdroid.views.overlay.Marker
import org.osmdroid.views.overlay.Polygon
import org.osmdroid.views.overlay.Polyline
import org.osmdroid.views.overlay.ScaleBarOverlay
import org.osmdroid.views.overlay.compass.CompassOverlay
import org.osmdroid.views.overlay.compass.InternalCompassOrientationProvider

class CustomAdapter(
    mainActivity: Context,
    private val names: Array<String>,
    private val mobile: Array<String>,
    private val emails: Array<String>,
    private val profile: Array<Int>
) : RecyclerView.Adapter<CustomAdapter.MyViewHolder>() {

    private val context = mainActivity

    init {
        Configuration.getInstance().load(
            context,
            android.preference.PreferenceManager.getDefaultSharedPreferences(context)
        )
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MyViewHolder {
        val view = LayoutInflater.from(parent.context).inflate(R.layout.custom, parent, false)
        return MyViewHolder(view)
    }

    override fun getItemCount(): Int = names.size

    override fun onBindViewHolder(holder: MyViewHolder, position: Int) {
        // Set user info
        holder.name.text = names[position]
        holder.email.text = emails[position]
        holder.mobile.text = mobile[position]
        holder.profile.setImageResource(profile[position])

        holder.profile.setOnClickListener {
            Toast.makeText(
                context,
                "Name: ${names[position]}\nEmail: ${emails[position]}\nMobile: ${mobile[position]}",
                Toast.LENGTH_LONG
            ).show()
        }

        holder.linearLayout.setOnClickListener {
            Toast.makeText(
                context,
                "Name: ${names[position]}\nEmail: ${emails[position]}\nMobile: ${mobile[position]}",
                Toast.LENGTH_LONG
            ).show()
        }

        // MapView setup
        holder.mapView.setMultiTouchControls(true)
        holder.mapView.controller.setZoom(10.0)

        // Compass overlay
        val compassOverlay = CompassOverlay(context, InternalCompassOrientationProvider(context), holder.mapView)
        compassOverlay.enableCompass()
        holder.mapView.overlays.add(compassOverlay)

        // Scale bar overlay
        val scaleBarOverlay = ScaleBarOverlay(holder.mapView)
        scaleBarOverlay.setCentred(true)
        holder.mapView.overlays.add(scaleBarOverlay)

        // Default tile source
        holder.mapView.setTileSource(TileSourceFactory.MAPNIK)

        // Dummy location for each item
        val latitude = 12.9716 + (position * 0.01)
        val longitude = 77.5946 + (position * 0.01)
        val geoPoint = GeoPoint(latitude, longitude)
        holder.mapView.controller.setCenter(geoPoint)

        // Marker overlay
        val marker = Marker(holder.mapView)
        marker.position = geoPoint
        marker.setAnchor(Marker.ANCHOR_CENTER, Marker.ANCHOR_BOTTOM)
        marker.title = names[position]

        // Polyline overlay
        val polyline = Polyline()
        polyline.addPoint(GeoPoint(latitude, longitude))
        polyline.addPoint(GeoPoint(latitude + 0.01, longitude + 0.01))
        polyline.addPoint(GeoPoint(latitude + 0.02, longitude))
        polyline.width = 5f
        polyline.color = Color.BLUE

        // Polygon overlay
        val polygon = Polygon()
        val polygonPoints = listOf(
            GeoPoint(latitude + 0.01, longitude - 0.01),
            GeoPoint(latitude + 0.01, longitude + 0.01),
            GeoPoint(latitude - 0.01, longitude + 0.01),
            GeoPoint(latitude - 0.01, longitude - 0.01)
        )
        polygon.points = polygonPoints
        polygon.fillColor = Color.parseColor("#3300FF00") // semi-transparent green
        polygon.strokeColor = Color.GREEN
        polygon.strokeWidth = 3f

        // Clear previous overlays and add new ones
        holder.mapView.overlays.clear()
        holder.mapView.overlays.add(marker)
        holder.mapView.overlays.add(polyline)
        holder.mapView.overlays.add(polygon)
        holder.mapView.overlays.add(compassOverlay)
        holder.mapView.overlays.add(scaleBarOverlay)
        holder.mapView.invalidate()

        // Spinner for tile sources
        val tileNames = context.resources.getStringArray(R.array.tile_sources)
        val adapter = ArrayAdapter(context, android.R.layout.simple_spinner_item, tileNames)
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item)
        holder.spinnerTile.adapter = adapter

        holder.spinnerTile.onItemSelectedListener = object : AdapterView.OnItemSelectedListener {
            override fun onItemSelected(parent: AdapterView<*>, view: View?, pos: Int, id: Long) {
                when (pos) {
                    0 -> holder.mapView.setTileSource(TileSourceFactory.MAPNIK)
                    1 -> holder.mapView.setTileSource(TileSourceFactory.USGS_TOPO)
                    2 -> holder.mapView.setTileSource(
                        XYTileSource(
                            "Watercolor",
                            0, 20, 256, ".png",
                            arrayOf("http://tile.stamen.com/watercolor/"),
                            "© Stamen Design"
                        )
                    )
                    3 -> holder.mapView.setTileSource(
                        XYTileSource(
                            "OpenTopoMap",
                            0, 17, 256, ".png",
                            arrayOf("https://tile.opentopomap.org/{z}/{x}/{y}.png"),
                            "© OpenTopoMap"
                        )
                    )
                }
                holder.mapView.invalidate()
            }

            override fun onNothingSelected(parent: AdapterView<*>) {}
        }
    }

    inner class MyViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
        val name: TextView = itemView.findViewById(R.id.name)
        val mobile: TextView = itemView.findViewById(R.id.mobile)
        val email: TextView = itemView.findViewById(R.id.email)
        val profile: ImageView = itemView.findViewById(R.id.iv)
        val linearLayout: LinearLayout = itemView.findViewById(R.id.linear)
        val mapView: MapView = itemView.findViewById(R.id.map)
        val spinnerTile: Spinner = itemView.findViewById(R.id.spinnerTile)
    }
}

Output:

TEXT FIELDS

E:\android\MyApplication\app\src\main\java\com\example\myapplication\MainActivity.kt

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="5dp"
        android:padding="5dp"
        android:text="Example Form"
        android:textAllCaps="true"
        android:textColor="#E91E63"
        android:textSize="20sp"
        android:textStyle="italic" />

    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="vertical">

            <EditText
                android:id="@+id/editTextTextPersonName"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_margin="5dp"
                android:ems="10"
                android:hint="textPersonName"
                android:inputType="textPersonName"
                android:padding="5dp"
                android:textAllCaps="true"
                android:textColor="#E91E63"
                android:textColorHint="#3F51B5"
                android:textSize="20sp"
                android:textStyle="italic" />

            <EditText
                android:id="@+id/editTextTextPassword"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_margin="5dp"
                android:ems="10"
                android:hint="textPassword"
                android:inputType="textPassword"
                android:padding="5dp"
                android:textAllCaps="true"
                android:textColor="#E91E63"
                android:textColorHint="#3F51B5"
                android:textSize="20sp"
                android:textStyle="italic" />

            <EditText
                android:id="@+id/editTextNumberPassword"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_margin="5dp"
                android:ems="10"
                android:hint="numberPassword"
                android:inputType="numberPassword"
                android:padding="5dp"
                android:textAllCaps="true"
                android:textColor="#E91E63"
                android:textColorHint="#3F51B5"
                android:textSize="20sp"
                android:textStyle="italic" />

            <EditText
                android:id="@+id/editTextTextEmailAddress"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_margin="5dp"
                android:ems="10"
                android:hint="textEmailAddress"
                android:inputType="textEmailAddress"
                android:padding="5dp"
                android:textAllCaps="true"
                android:textColor="#E91E63"
                android:textColorHint="#3F51B5"
                android:textSize="20sp"
                android:textStyle="italic" />

            <EditText
                android:id="@+id/editTextTextMultiLine"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_margin="5dp"
                android:ems="10"
                android:gravity="start|top"
                android:hint="textMultiLine"
                android:inputType="textMultiLine"
                android:minLines="10"
                android:padding="5dp"
                android:textAllCaps="true"
                android:textColor="#E91E63"
                android:textColorHint="#3F51B5"
                android:textSize="20sp"
                android:textStyle="italic" />

            <EditText
                android:id="@+id/editTextTextPostalAddress"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_margin="5dp"
                android:ems="10"
                android:hint="textPostalAddress"
                android:inputType="textPostalAddress"
                android:padding="5dp"
                android:textAllCaps="true"
                android:textColor="#E91E63"
                android:textColorHint="#3F51B5"
                android:textSize="20sp"
                android:textStyle="italic" />

            <EditText
                android:id="@+id/editTextTime"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_margin="5dp"
                android:ems="10"
                android:hint="time"
                android:inputType="time"
                android:padding="5dp"
                android:textAllCaps="true"
                android:textColor="#E91E63"
                android:textColorHint="#3F51B5"
                android:textSize="20sp"
                android:textStyle="italic" />

            <EditText
                android:id="@+id/editTextNumber"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_margin="5dp"
                android:ems="10"
                android:hint="number"
                android:inputType="number"
                android:padding="5dp"
                android:textAllCaps="true"
                android:textColor="#E91E63"
                android:textColorHint="#3F51B5"
                android:textSize="20sp"
                android:textStyle="italic" />

            <EditText
                android:id="@+id/editTextNumberSigned"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_margin="5dp"
                android:ems="10"
                android:hint="numberSigned"
                android:inputType="numberSigned"
                android:padding="5dp"
                android:textAllCaps="true"
                android:textColor="#E91E63"
                android:textColorHint="#3F51B5"
                android:textSize="20sp"
                android:textStyle="italic" />

            <EditText
                android:id="@+id/editTextNumberDecimal"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_margin="5dp"
                android:ems="10"
                android:hint="numberDecimal"
                android:inputType="numberDecimal"
                android:padding="5dp"
                android:textAllCaps="true"
                android:textColor="#E91E63"
                android:textColorHint="#3F51B5"
                android:textSize="20sp"
                android:textStyle="italic" />

            <Button
                android:id="@+id/bt"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:text="Submit"></Button>
        </LinearLayout>
    </ScrollView>

</LinearLayout>

E:\android\MyApplication\app\src\main\java\com\example\myapplication\MainActivity.kt

package com.example.myapplication

import android.annotation.SuppressLint
import android.os.Bundle
import android.widget.Button
import android.widget.EditText


import android.widget.Toast
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity

class MainActivity : AppCompatActivity() {

    var button: Button? = null
    var e1: EditText? = null
    var e2: EditText? = null


    @SuppressLint("WrongConstant")
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        // Enable edge-to-edge content
        enableEdgeToEdge()

        button = findViewById(R.id.bt)
        e1 = findViewById(R.id.editTextTextPersonName)
        e2 = findViewById(R.id.editTextTextPassword)

        button!!.setOnClickListener {
            var s1: String = e1!!.text.toString()
            var s2: String = e2!!.text.toString()
            Toast.makeText(applicationContext, s1 + s2, Toast.LENGTH_LONG).show()
        }


    }
}

Output

Implicit Intent example

E:\android\MyApplication\app\src\main\AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">

    <application
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.MyApplication">
        <activity
            android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

E:\android\MyApplication\app\src\main\res\layout\activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<layout>
    <LinearLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".MainActivity"
        android:orientation="vertical">
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Implicit Intent eaxmple!"
            />
        <Button
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="Camera "
            android:id="@+id/camera"/>
        <Button
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="Browser "
            android:id="@+id/browser"/>
        <Button
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="Gallary "
            android:id="@+id/gallary"/>
    </LinearLayout>
</layout>

E:\android\MyApplication\app\src\main\res\layout\activity_main.xml

package com.example.myapplication

import android.annotation.SuppressLint
import android.content.Intent
import android.net.Uri
import android.os.Bundle
import android.provider.MediaStore
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity
import androidx.databinding.DataBindingUtil
import com.example.myapplication.databinding.ActivityMainBinding

class MainActivity : AppCompatActivity() {
    var binding: ActivityMainBinding?=null


    @SuppressLint("WrongConstant")
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        // Enable edge-to-edge content
        enableEdgeToEdge()
        binding=DataBindingUtil.setContentView(this,R.layout.activity_main)

        binding?.camera?.setOnClickListener {
            var intent= Intent(MediaStore.ACTION_IMAGE_CAPTURE)
            startActivity(intent)
        }
        binding?.browser?.setOnClickListener {
            var intent= Intent(android.content.Intent.ACTION_VIEW)
            intent.data= Uri.parse("https://androindian.com/registration-usingretrofit-raw-data/")
            startActivity(intent)
        }
        binding?.gallary?.setOnClickListener {
            var intent= Intent(Intent.ACTION_PICK)
            // intent.setType("image/*")
            intent.setType("video/*")
            // intent.setType("doc/*")
            startActivity(intent)
        }

    }
}

Output

Neo4j graph database 

C:\Users\nani\.Neo4jDesktop2\Data\dbmss\dbms-19e81f2e-5ce7-4140-8a6d-534b71e97aa7\bin
SET JAVA_HOME=C:\Program Files\Java\jdk-24.0.2
SET PATH=%JAVA_HOME%\bin;%PATH%
neo4j.bat console

Data Sci Side 

Networkx

R-GNN (Advanced Relational ML Models Lavel 4 ML Topic)

Using pyTorch Module form O2O,O2M,M2M Relational ML Models 

at Ubantuos

http://localhost:7474/browser/

welcome@1234

Project/JyothsnaLead

Date - 01/Dec/2025 - Project Title selection 

If Guild and coodinater and HOD :

    Pass

B4 22HN1A3952 SHAIK ANEEF 

 22HN1A3904 BANDI CHENCHU KRISHNA

 22HN1A3907 BOMMISETTY SRINIVASA GANESH

 22HN1A3934 MAMUDURU VENKAT LOCHANDU

 22HN1A3905 BATTHALA LAKSHMI PRASANNA

05/12/2025

952,904 is present 

Absentees 

905 - rain issue

934 - siter marriage 

907 - bank Holiday 

Project Title submission process 

Project Team

22HN1A3941 NALABOTHU JYOTHSNA 

22HN1A3922 GANUGAPENTA NIHARIKA

22HN1A3966 YELLURI VIJAY KRISHNA KUMAR

22HN1A3902 BACHU MAHESH

22HN1A3909 CHALLA KAVYA

Project Title time

05/12/2025(Friday)

Project title Submission 

941,22,66 - prasent 

Abs

909 - health issues 

902 - transport issue 

1. Setup and Configuration of Edge Devices 

   Raspberry Pi/Jetson Nano installation, SSH, GPIO control

1. Setup and Configuration of Edge Devices

Raspberry Pi / Jetson Nano Installation, SSH Access, and GPIO Control

A. Operating System Installation

Raspberry Pi

• Download the Raspberry Pi OS using the Raspberry Pi Imager tool.

• Flash the OS to an SD card (16GB+ recommended).

• Enable SSH and configure Wi-Fi during flashing (optional using Imager advanced options).

• Insert SD card → Power on → Device boots with default credentials.

B. Remote Access (SSH Configuration)

On Raspberry Pi

Enable SSH:

sudo systemctl enable ssh 
sudo systemctl start ssh

Connect from your laptop:

ssh pi@<device-ip> 

To find device IP:

ifconfig

C. GPIO (General Purpose Input/Output) Control

Raspberry Pi (Python – RPi.GPIO or GPIO Zero)

Example using RPi.GPIO:

import RPi.GPIO as GPIO
import time

GPIO.setmode(GPIO.BCM)
GPIO.setup(18, GPIO.OUT)

while True:
    GPIO.output(18, True)
    time.sleep(1)
    GPIO.output(18, False)
    time.sleep(1)

D. Additional Recommended Setup

• Setup VNC for GUI remote access.

• Setup Docker for deploying applications.

• Create virtual environments for Python projects.

• Use systemd services to auto-run scripts on boot.

• Configure I2C, SPI, UART interfaces as needed.

E. Typical Use Cases

• AI object detection (Jetson Nano + camera).

• IoT sensor hub (Raspberry Pi + GPIO sensors).

• Edge inference for ML models.

• Robotics and industrial automation.

• Home automation systems.

pi@raspberrypi:~ $ pinout

,--------------------------------.
| oooooooooooooooooooo J8   +======
| 1ooooooooooooooooooo  PoE |   Net
|  Wi                    1o +======
|  Fi  Pi Model 4B  V1.4 oo      |
|        ,----. +---+         +====
| |D|    |SoC | |RAM|         |USB3
| |S|    |    | |   |         +====
| |I|    `----' +---+            |
|                   |C|       +====
|                   |S|       |USB2
| pwr   |hd|   |hd| |I||A|    +====
`-| |---|m0|---|m1|----|V|-------'

Revision           : d03114
SoC                : BCM2711
RAM                : 8GB
Storage            : MicroSD
USB ports          : 4 (of which 2 USB3)
Ethernet ports     : 1 (1000Mbps max. speed)
Wi-fi              : True
Bluetooth          : True
Camera ports (CSI) : 1
Display ports (DSI): 1

J8:
   3V3  (1) (2)  5V    
 GPIO2  (3) (4)  5V    
 GPIO3  (5) (6)  GND   
 GPIO4  (7) (8)  GPIO14
   GND  (9) (10) GPIO15
GPIO17 (11) (12) GPIO18
GPIO27 (13) (14) GND   
GPIO22 (15) (16) GPIO23
   3V3 (17) (18) GPIO24
GPIO10 (19) (20) GND   
 GPIO9 (21) (22) GPIO25
GPIO11 (23) (24) GPIO8 
   GND (25) (26) GPIO7 
 GPIO0 (27) (28) GPIO1 

Here Check Status Of GPIO Pins 

pi@raspberrypi:~ $ raspi-gpio get
BANK0 (GPIO 0 to 27):
GPIO 0: level=1 fsel=0 func=INPUT pull=UP
GPIO 1: level=1 fsel=0 func=INPUT pull=UP
GPIO 2: level=1 fsel=0 func=INPUT pull=UP
GPIO 3: level=1 fsel=0 func=INPUT pull=UP
GPIO 4: level=1 fsel=0 func=INPUT pull=UP
GPIO 5: level=1 fsel=0 func=INPUT pull=UP
GPIO 6: level=1 fsel=0 func=INPUT pull=UP
GPIO 7: level=1 fsel=0 func=INPUT pull=UP
GPIO 8: level=1 fsel=0 func=INPUT pull=UP
GPIO 9: level=0 fsel=0 func=INPUT pull=DOWN
GPIO 10: level=0 fsel=0 func=INPUT pull=DOWN
GPIO 11: level=0 fsel=0 func=INPUT pull=DOWN
GPIO 12: level=0 fsel=0 func=INPUT pull=DOWN
GPIO 13: level=0 fsel=0 func=INPUT pull=DOWN
GPIO 14: level=0 fsel=0 func=INPUT pull=NONE
GPIO 15: level=1 fsel=0 func=INPUT pull=UP
GPIO 16: level=0 fsel=0 func=INPUT pull=DOWN
GPIO 17: level=0 fsel=0 func=INPUT pull=DOWN
GPIO 18: level=0 fsel=0 func=INPUT pull=DOWN
GPIO 19: level=0 fsel=0 func=INPUT pull=DOWN
GPIO 20: level=0 fsel=0 func=INPUT pull=DOWN
GPIO 21: level=0 fsel=0 func=INPUT pull=DOWN
GPIO 22: level=0 fsel=0 func=INPUT pull=DOWN

import pandas as pd
dir(pd.DataFrame)

Output:

 [
.....
'pipe',
 'pivot',
 'pivot_table',
 'plot',
 'pop'
...
]

Progarm

print(pd.DataFrame.plot.__doc__)

Output

Make plots of Series or DataFrame.

    Uses the backend specified by the
    option ``plotting.backend``. By default, matplotlib is used.

    Parameters
    ----------
    data : Series or DataFrame
        The object for which the method is called.
    x : label or position, default None
        Only used if data is a DataFrame.
    y : label, position or list of label, positions, default None
        Allows plotting of one column versus another. Only used if data is a
        DataFrame.
    kind : str
        The kind of plot to produce:

        - 'line' : line plot (default)
        - 'bar' : vertical bar plot
        - 'barh' : horizontal bar plot
        - 'hist' : histogram
        - 'box' : boxplot
        - 'kde' : Kernel Density Estimation plot
        - 'density' : same as 'kde'
        - 'area' : area plot
        - 'pie' : pie plot
        - 'scatter' : scatter plot (DataFrame only)
        - 'hexbin' : hexbin plot (DataFrame only)

Program

dict = {"country": ["Brazil", "Russia", "India", "China", "South Africa"],
       "capital": ["Brasilia", "Moscow", "New Dehli", "Beijing", "Pretoria"],
       "area": [8.516, 17.10, 3.286, 9.597, 1.221],
        "count01": [8.516, 17.10, 3.286, 9.597, 1.221],
       "population": [200.4, 143.5, 1252, 1357, 52.98] }
brics = pd.DataFrame(dict)

print(brics)

Output

        country    capital    area  count01  population
0        Brazil   Brasilia   8.516    8.516      200.40
1        Russia     Moscow  17.100   17.100      143.50
2         India  New Dehli   3.286    3.286     1252.00
3         China    Beijing   9.597    9.597     1357.00
4  South Africa   Pretoria   1.221    1.221       52.98

Program

# ---------------------------
# 1. BAR PLOT (Area by Country)
# ---------------------------
brics.plot(kind='bar', x='country', y='area', title='Area of BRICS Countries')
plt.ylabel("Area (million sq km)")
plt.show()

# -----------------------------------
# 2. HISTOGRAM (Population distribution)
# -----------------------------------
brics['population'].plot(kind='hist', title='Population Histogram')
plt.xlabel("Population (millions)")
plt.show()

# ---------------------------
# 3. LINE PLOT (Area trend)
# ---------------------------
brics.plot(kind='line', x='country', y='area', title='Area Line Plot')
plt.ylabel("Area (million sq km)")
plt.show()

# -----------------------------------------
# 4. SCATTER PLOT (Area vs Population)
# -----------------------------------------
brics.plot(kind='scatter', x='area', y='population',
           title='Scatter Plot: Area vs Population')
plt.xlabel("Area (million sq km)")
plt.ylabel("Population (millions)")
plt.show()

Output

Program

import networkx as nx
import matplotlib.pyplot as plt
dir(nx)
print(nx.Graph.__doc__)

G = nx.Graph()
G.add_weighted_edges_from([ ('Atmakur', 'Marripadu', 43), ('Atmakur', 'Sangam', 17), ('Marripadu', 'Appiligunta', 10), ('Marripadu', 'Badvel', 51), ('Marripadu', 'Pallolu', 5), ('Sangam', 'Padalakure', 20), ('Sangam', 'Nellore', 60)], color="red")

G
plt.axis('off')
nx.draw_networkx(G,node_size=600,font_color='white')

Output:

3. Write a Program to Implement Breadth First Search using Python.
Program using Predefined Function Call

bfs_nodes = list(nx.bfs_tree(G, source='Atmakur'))
print("BFS Traversal:", bfs_nodes)

Output

BFS Traversal: ['Atmakur', 'Marripadu', 'Sangam', 'Appiligunta', 'Badvel', 'Pallolu', 'Padalakure', 'Nellore']

Program using User Denied  Function Call

visited = []

def dfs(visited, graph, node):
    if node not in visited:
        print(f"{node} has been visited")
        visited.append(node)
        for neighbor in graph[node]:
            visited = dfs(visited, graph, neighbor)

    return visited

dfs(visited, G, 'Atmakur')

Output:

Atmakur has been visited
Marripadu has been visited
Appiligunta has been visited
Badvel has been visited
Pallolu has been visited
Sangam has been visited
Padalakure has been visited
Nellore has been visited
['Atmakur',
 'Marripadu',
 'Appiligunta',
 'Badvel',
 'Pallolu',
 'Sangam',
 'Padalakure',
 'Nellore']

5. Write a Program to Implement Depth First Search using Python.

Pre Fun()

dfs_nodes = list(nx.dfs_tree(G, source='Atmakur'))
print("DFS Traversal:", dfs_nodes)

Output:

DFS Traversal: ['Atmakur', 'Marripadu', 'Appiligunta', 'Badvel', 'Pallolu', 'Sangam', 'Padalakure', 'Nellore']

User Fun() :

visited = []

def dfs(visited, graph, node):
    if node not in visited:
        print(f"{node} has been visited")
        visited.append(node)
        for neighbor in graph[node]:
            visited = dfs(visited, graph, neighbor)

    return visited

dfs(visited, G, 'Atmakur')

Output:

Atmakur has been visited
Marripadu has been visited
Appiligunta has been visited
Badvel has been visited
Pallolu has been visited
Sangam has been visited
Padalakure has been visited
Nellore has been visited
['Atmakur',
 'Marripadu',
 'Appiligunta',
 'Badvel',
 'Pallolu',
 'Sangam',
 'Padalakure',
 'Nellore']

4. Write a program to implement Best First Searching Algorithm

Program

from queue import PriorityQueue

def best_first_search(graph, start, goal, h):
    pq = PriorityQueue()
    pq.put((h.get(start, 0), start))
    visited = set()

    while not pq.empty():
        _, node = pq.get()
        print("Visiting:", node)

        if node == goal:
            return "Goal Reached"

        visited.add(node)

        for neighbor in graph.neighbors(node):
            if neighbor not in visited:
                pq.put((h.get(neighbor, 0), neighbor))

    return "Goal Not Found"
print("Best First Search Result:",best_first_search(G, 'Atmakur', 'Badvel', heuristic))

Output:

Visiting: Atmakur
Visiting: Marripadu
Visiting: Appiligunta
Visiting: Badvel
Best First Search Result: Goal Reached

6. Write a program to implement the Heuristic Search

Program

heuristic = {
    'Atmakur': 60,
    'Marripadu': 45,
    'Sangam': 50,
    'Appiligunta': 30,
    'Badvel': 25,
    'Pallolu': 20,
    'Padalakure': 15,
    'Nellore': 0
}

from queue import PriorityQueue

def heuristic_search(graph, start, goal, h):
    pq = PriorityQueue()
    pq.put((h[start], start))
    visited = set()

    while not pq.empty():
        _, node = pq.get()
        print("Visiting:", node)

        if node == goal:
            return "Goal reached"

        visited.add(node)

        for neighbor in graph.neighbors(node):
            if neighbor not in visited:
                pq.put((h[neighbor], neighbor))

    return "Goal not found"

print(heuristic_search(G, 'Atmakur', 'Nellore', heuristic))

Output:

Visiting: Atmakur
Visiting: Marripadu
Visiting: Pallolu
Visiting: Badvel
Visiting: Appiligunta
Visiting: Sangam
Visiting: Nellore
Goal reached

7. Write a python program to implement A* and AO* algorithm. (Ex: find the shortest path)

Program A*

astar_path = nx.astar_path(
    G,
    'Atmakur',
    'Nellore',
    heuristic=lambda n, goal=None: heuristic[n],
    weight='weight'
)

print("A* Path:", astar_path)
print("Total Cost:", nx.path_weight(G, astar_path, weight='weight'))

Output:

A* Path: ['Atmakur', 'Sangam', 'Nellore']
Total Cost: 77

Program AO*

import math

AO = nx.DiGraph()


# Add edges with weights from your towns data
edges = [
    ('Atmakur', 'Marripadu', 43),
    ('Atmakur', 'Sangam', 17),
    ('Marripadu', 'Appiligunta', 10),
    ('Marripadu', 'Badvel', 51),
    ('Marripadu', 'Pallolu', 5),
    ('Sangam', 'Padalakure', 20),
    ('Sangam', 'Nellore', 60)
]

for u, v, w in edges:
    AO.add_edge(u, v, weight=w)


heuristic_ao = {
    'Atmakur': 60,
    'Marripadu': 45,
    'Sangam': 50,
    'Appiligunta': 30,
    'Badvel': 25,
    'Pallolu': 20,
    'Padalakure': 15,
    'Nellore': 0
}

def ao_star(node):
    if node not in AO or AO.out_degree(node) == 0:
        return heuristic_ao[node]

    costs = []
    for child in AO.successors(node):
        cost = AO[node][child]['weight'] + ao_star(child)
        costs.append(cost)

    return min(costs)

print("AO* Minimum Cost from Nellore:", ao_star('Atmakur'))

Output

AO* Minimum Cost from Nellore: 52

Explanation

Graph edges (distances):

Atmakur → Marripadu (43)

Atmakur → Sangam (17)

Marripadu → Appiligunta (10)

Marripadu → Badvel (51)

Marripadu → Pallolu (5)

Sangam → Padalakure (20)

Sangam → Nellore (60)

Heuristic values (estimated distance to goal):

Atmakur: 60

Marripadu: 45

Sangam: 50

Appiligunta: 30

Badvel: 25

Pallolu: 20

Padalakure: 15

Nellore: 0

Step 1: AO* starts at Atmakur

• It looks at successors: 'Marripadu' and 'Sangam'
• Recursively calculates cost for each child

Step 2: Calculate cost via 'Marripadu'

• Cost = edge weight (Atmakur → Marripadu) + AO*(Marripadu)
• Edge weight = 43

AO*(Marripadu)

• Successors: 'Appiligunta', 'Badvel', 'Pallolu'

1. Marripadu → Appiligunta: 10 + heuristic(Appiligunta=30) = 10 + 30 = 40
2. Marripadu → Badvel: 51 + heuristic(Badvel=25) = 51 + 25 = 76
3. Marripadu → Pallolu: 5 + heuristic(Pallolu=20) = 5 + 20 = 25

• AO* takes minimum: min(40, 76, 25) = 25
• Total cost via 'Marripadu' = 43 + 25 = 68

Step 3: Calculate cost via 'Sangam'

• Cost = edge weight (Atmakur → Sangam) + AO*(Sangam)
• Edge weight = 17

AO*(Sangam)

• Successors: 'Padalakure', 'Nellore'

1. Sangam → Padalakure: 20 + heuristic(Padalakure=15) = 35
2. Sangam → Nellore: 60 + heuristic(Nellore=0) = 60

• AO* takes minimum: min(35, 60) = 35
• Total cost via 'Sangam' = 17 + 35 = 52

Step 4: Choose minimum at root 'Atmakur'

• Costs:
  • Via Marripadu: 68
  • Via Sangam: 52
• AO* takes minimum: min(68, 52) = 52 ✅

✅ Result

AO* Minimum Cost from Atmakur: 52

Path implied (by AO*):

Atmakur → Sangam → Padalakure

• Total cost = 17 (Atmakur→Sangam) + 20 (Sangam→Padalakure) + 15 (heuristic of Padalakure) = 52

Note: Currently your code returns only the cost, not the path.
If you want, I can modify it to also return the exact path, so you can see ['Atmakur', 'Sangam', 'Padalakure'].

5. MQTT-Based Edge Communication o Setup publisher/subscriber model for edge-to-cloud communication

REQUIRED LIBRARY (on Raspberry Pi)

pip install Adafruit-DHT

FINAL IMPROVED CODE (LED + DHT11 via MQTT)

import time
import RPi.GPIO as GPIO
import paho.mqtt.client as mqtt
import board
import adafruit_dht

# ---------------- GPIO SETUP ----------------
GPIO.setmode(GPIO.BCM)
GPIO.setwarnings(False)

LED_PIN = 18
GPIO.setup(LED_PIN, GPIO.OUT)

# ---------------- DHT11 SETUP ----------------
dhtDevice = adafruit_dht.DHT11(board.D4)

# ---------------- MQTT SETUP ----------------
BROKER = "192.168.0.161"
TOPIC_CMD = "led/cmd"
TOPIC_STATUS = "led/status"
TOPIC_DHT = "sensor/dht11"

# ---------------- STATE ----------------
led_state = False   # change detector

# ---------------- CALLBACKS ----------------
def on_connect(client, userdata, flags, rc):
    print("Connected:", rc)
    client.subscribe(TOPIC_CMD)

def on_message(client, userdata, msg):
    global led_state
    payload = msg.payload.decode().lower()
    print("MQTT:", payload)

    # -------- OFF → ON (CHANGE SIGNAL) --------
    if payload == "on" and not led_state:
        led_state = True
        GPIO.output(LED_PIN, GPIO.HIGH)
        client.publish(TOPIC_STATUS, "ON")

        # ---- READ DHT11 ONCE ----
        try:
            temperature = dhtDevice.temperature
            humidity = dhtDevice.humidity

            if temperature is not None and humidity is not None:
                data = f"Temp={temperature}C Humidity={humidity}%"
                client.publish(TOPIC_DHT, data)
                print("DHT:", data)

        except RuntimeError as error:
            print("DHT error:", error)

    # -------- ON → OFF (CHANGE SIGNAL) --------
    elif payload == "off" and led_state:
        led_state = False
        GPIO.output(LED_PIN, GPIO.LOW)
        client.publish(TOPIC_STATUS, "OFF")

def on_disconnect(client, userdata, rc):
    print("Disconnected")

# ---------------- MQTT CLIENT ----------------
client = mqtt.Client()
client.on_connect = on_connect
client.on_message = on_message
client.on_disconnect = on_disconnect

client.connect(BROKER, 1883, 60)
client.loop_forever()

Example Output

MQTT: on
DHT: Temp=28C Humidity=65%
DHT: Temp=28C Humidity=64%
MQTT: off

Case02

import time
from time import sleep
import os,sys
import RPi.GPIO as GPIO
import paho.mqtt.client as paho

GPIO.setmode(GPIO.BCM)
GPIO.setwarnings(False)
LED_PIN=18  #define LED pin
GPIO.setup(LED_PIN,GPIO.OUT)   # Set pin function as output


def on_connect(self, mosq, obj, rc):
        self.subscribe("led", 0)
    
def on_message(mosq, obj, msg):
    #print(msg.topic + " " + str(msg.qos) + " " + str(msg.payload))
    if(msg.payload.decode().lower() == 'on'):    
        print("LED on")
        #sleep(5)
        GPIO.output(LED_PIN, 1)  #LED ON
        sleep(0.2)
    elif(msg.payload.decode().lower() == 'off'): 
        print("LED off") 
        #sleep(5)
        GPIO.output(LED_PIN,0)   # LED OFF
        sleep(0.2)

def on_publish(mosq, obj, mid):
    #print("mid: " + str(mid))
    pass

    
def on_subscribe(mosq, obj, mid, granted_qos):
    print("Subscribed: " + str(mid) + " " + str(granted_qos))



mqttc = paho.Client()                        # object declaration
# Assign event callbacks
mqttc.on_message = on_message                          # called as callback
mqttc.on_connect = on_connect
mqttc.on_publish = on_publish
mqttc.on_subscribe = on_subscribe

mqttc.connect('192.168.0.161', 1883)

rc = 0
flag = 0
flag1 = 0
while True:
    input_state=bool(GPIO.input(18))
    rc = mqttc.loop()
    if flag==0:
        mqttc.publish("led",'Status :'+str(GPIO.input(18)))
        flag=1
    if input_state==False:
        if flag1==0:
            print('Button Not Pressed')
            flag1=1
            flag=0
    elif input_state==True:
        if flag1==1:
            print('Button Pressed')
            flag1=0
            flag=0

Testing From OnBard raspberry Pi(192.168.0.161)

import time
from time import sleep
import os,sys
import RPi.GPIO as GPIO
import paho.mqtt.client as paho

GPIO.setmode(GPIO.BCM)
GPIO.setwarnings(False)
LED_PIN=18  #define LED pin
GPIO.setup(LED_PIN,GPIO.OUT)   # Set pin function as output
GPIO.output(LED_PIN,0)

GPIO.output(LED_PIN,1) #On
GPIO.output(LED_PIN,0) #OFF

Using MQTT Msg Publish

On Way Case 

pi@raspberrypi:~ $ mosquitto_pub -h 192.168.0.161 -t led -m "on"
pi@raspberrypi:~ $ mosquitto_pub -h 192.168.0.161 -t led -m "oN"
pi@raspberrypi:~ $ mosquitto_pub -h 192.168.0.161 -t led -m "On"
pi@raspberrypi:~ $ mosquitto_pub -h 192.168.0.161 -t led -m "ON"

OFF Way Case

pi@raspberrypi:~ $ mosquitto_pub -h 192.168.0.161 -t led -m "off"
pi@raspberrypi:~ $ mosquitto_pub -h 192.168.0.161 -t led -m "Off"
pi@raspberrypi:~ $ mosquitto_pub -h 192.168.0.161 -t led -m "oFf"
pi@raspberrypi:~ $ mosquitto_pub -h 192.168.0.161 -t led -m "OFF"