RadioGroup - Android Widgets Example

package com.myapp;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.RadioButton;
import android.widget.Toast;

public class MainActivity extends Activity {
	
	RadioButton myOption1, myOption2, myOption3;
	
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        myOption1 = (RadioButton)findViewById(R.id.radio1);
        myOption2 = (RadioButton)findViewById(R.id.radio2);
        myOption3 = (RadioButton)findViewById(R.id.radio3);
        myOption1.setOnClickListener(myOptionOnClickListener);
        myOption2.setOnClickListener(myOptionOnClickListener);
        myOption3.setOnClickListener(myOptionOnClickListener);
    }
    
    RadioButton.OnClickListener myOptionOnClickListener =
 		   new RadioButton.OnClickListener()
 		  {
 		
	 		  public void onClick(View v) {
	 		   // TODO Auto-generated method stub
	 		   Toast.makeText(MainActivity.this,
	 		     "RadioButton 1 : " + myOption1.isChecked() + "\n"+
	 		     "RadioButton 2 : " + myOption2.isChecked() + "\n" +
	 		     "RadioButton 3 : " + myOption3.isChecked(),
	 		     Toast.LENGTH_LONG).show();
 		
	 		  }
	 		};

   
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    }

}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <RadioGroup
        android:id="@+id/radioGroup1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="53dp" >

        <RadioButton
            android:id="@+id/radio1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:checked="true"
            android:text="RadioButton 1" />

        <RadioButton
            android:id="@+id/radio2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="RadioButton 2" />

        <RadioButton
            android:id="@+id/radio3"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="RadioButton 3" />
    </RadioGroup>

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/radioGroup1"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="16dp"
        android:text="Button" />

</RelativeLayout>