This document describes an Android application that allows a user to select their favorite color from a radio button group. The application contains an XML layout file that defines the user interface including text labels, radio buttons for red, blue, green, yellow and gray, and a submit button. It also includes a Java class that implements the application logic to detect which radio button is selected when the user clicks submit, display the selected color name in a text view and change the background color of the layout.

1. Android App with Radio button group – NITHIYAPRIYA PASAVARAJ
Android Application with Radio Button
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"
android:orientation="vertical"
tools:context=".MainActivity" >
<LinearLayout
android:id="@+id/lnrlayout"
android:layout_width="fill_parent"
android:layout_height="756dp"
android:orientation="vertical">
<TextView
android:id="@+id/textView2"

2. Android App with Radio button group – NITHIYAPRIYA PASAVARAJ
android:layout_width="wrap_content"
android:layout_height="72dp"
android:text="Select Your Favorite Color"
android:textColor="#7B1FA2"
android:textSize="30sp"
android:textStyle="bold"
tools:layout_conversion_absoluteHeight="61dp"
tools:layout_conversion_absoluteWidth="388dp"
tools:layout_editor_absoluteX="0dp"
tools:layout_editor_absoluteY="0dp" />
<RadioGroup
android:layout_width="355dp"
android:layout_height="397dp">
<RadioButton
android:id="@+id/clrred"
android:layout_width="match_parent"
android:layout_height="47dp"
android:layout_weight="1"
android:checked="false"
android:text="Red"
android:textAllCaps="true"
android:textColor="#E64A19"
android:textSize="24sp"
android:textStyle="bold|italic" />
<RadioButton
android:id="@+id/clrblue"
android:layout_width="match_parent"
android:layout_height="43dp"
android:layout_weight="1"
android:checked="false"
android:text="Blue"
android:textAllCaps="true"
android:textColor="#512DA8"
android:textSize="24sp"
android:textStyle="bold|italic" />
<RadioButton
android:id="@+id/clrgreen"
android:layout_width="match_parent"
android:layout_height="wrap_content"

3. Android App with Radio button group – NITHIYAPRIYA PASAVARAJ
android:layout_weight="1"
android:text="Green"
android:textAllCaps="true"
android:textColor="#00796B"
android:textSize="24sp"
android:textStyle="bold|italic" />
<RadioButton
android:id="@+id/clryellow"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="Yellow"
android:textAllCaps="true"
android:textColor="#FBC02D"
android:textSize="24sp"
android:textStyle="bold|italic" />
<RadioButton
android:id="@+id/clrorange"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="Gray"
android:textAllCaps="true"
android:textColor="#A3A39F"
android:textSize="24sp"
android:textStyle="bold|italic" />
</RadioGroup>
<Button
android:id="@+id/btnsubmit"
android:layout_width="180dp"
android:layout_height="60dp"
android:layout_gravity="center"
android:background="#9DC218"
android:text="Submit"
android:textAllCaps="true"
android:textColor="#7B1FA2"
android:textSize="30sp"
android:textStyle="bold" />

4. Android App with Radio button group – NITHIYAPRIYA PASAVARAJ
<TextView
android:id="@+id/txtview"
android:layout_width="match_parent"
android:layout_height="132dp"
android:textSize="30sp"
android:textStyle="bold" />
</LinearLayout>
</LinearLayout>
Mainactivity.java
package com.example.radiobtngrp;
import androidx.appcompat.app.AppCompatActivity;
import android.graphics.Color;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.RadioButton;
import android.widget.TextView;
public class MainActivity extends AppCompatActivity {
RadioButton red,blue,green,yellow,orange;
Button btnsubmit;
TextView txtview;
LinearLayout lnrlayout;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
red=(RadioButton )findViewById(R.id.clrred);
blue = (RadioButton)findViewById(R.id.clrblue);
green = (RadioButton)findViewById(R.id.clrgreen);
orange = (RadioButton)findViewById(R.id.clrorange);
yellow = (RadioButton)findViewById(R.id.clryellow);
btnsubmit = (Button)findViewById(R.id.btnsubmit);
txtview = (TextView)findViewById(R.id.txtview) ;
lnrlayout = (LinearLayout) findViewById(R.id.lnrlayout);
btnsubmit.setOnClickListener(new View.OnClickListener() {
@Override

5. Android App with Radio button group – NITHIYAPRIYA PASAVARAJ
public void onClick(View view) {
if(red.isChecked())
{
txtview.setText("You've Selected Red");
lnrlayout.setBackgroundColor(Color.RED);
}
if(blue.isChecked())
{
txtview.setText("You've Selected Blue");
lnrlayout.setBackgroundColor(Color.BLUE);
}
if(green.isChecked())
{
txtview.setText("You've Selected Green");
lnrlayout.setBackgroundColor(Color.GREEN);
}
if(yellow.isChecked())
{
txtview.setText("You've Selected Yellow");
lnrlayout.setBackgroundColor(Color.YELLOW);
}
if(orange.isChecked())
{
txtview.setText("You've Selected Gray");
lnrlayout.setBackgroundColor(Color.DKGRAY);
//lnrlayout.setBackgroundColor(-565);
}
}
});
}
}