<LinearLayout 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”
android:orientation=”vertical”
tools:context=”.MainActivity” >

<LinearLayout
android:layout_width=”match_parent”
android:layout_height=”wrap_content” >

<TextView
android:id=”@+id/textView1″
android:layout_width=”wrap_content”
android:layout_height=”wrap_content”
android:text=”TextView” />

</LinearLayout>

<LinearLayout
android:layout_width=”match_parent”
android:layout_height=”wrap_content” >

<Button
android:id=”@+id/button1″
android:layout_width=”wrap_content”
android:layout_height=”wrap_content”
android:text=”Button” />

<Button
android:id=”@+id/button2″
android:layout_width=”wrap_content”
android:layout_height=”wrap_content”
android:text=”Button” />

<Button
android:id=”@+id/button3″
android:layout_width=”wrap_content”
android:layout_height=”wrap_content”
android:text=”Button” />

</LinearLayout>

<LinearLayout
android:layout_width=”match_parent”
android:layout_height=”wrap_content” >

<Button
android:id=”@+id/button4″
android:layout_width=”wrap_content”
android:layout_height=”wrap_content”
android:text=”Button” />

<Button
android:id=”@+id/button5″
android:layout_width=”wrap_content”
android:layout_height=”wrap_content”
android:text=”Button” />

<Button
android:id=”@+id/button6″
android:layout_width=”wrap_content”
android:layout_height=”wrap_content”
android:text=”Button” />

</LinearLayout>

<LinearLayout
android:layout_width=”match_parent”
android:layout_height=”wrap_content” >

<Button
android:id=”@+id/button7″
android:layout_width=”wrap_content”
android:layout_height=”wrap_content”
android:text=”Button” />

<Button
android:id=”@+id/button8″
android:layout_width=”wrap_content”
android:layout_height=”wrap_content”
android:text=”Button” />

<Button
android:id=”@+id/button9″
android:layout_width=”wrap_content”
android:layout_height=”wrap_content”
android:text=”Button” />

</LinearLayout>

</LinearLayout>

package com.btnarray;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class MainActivity extends Activity {
public int []m_id={R.id.button1,R.id.button2,R.id.button3,R.id.button4,R.id.button5,R.id.button6,R.id.button7,R.id.button8,R.id.button9};
public Button []m_btn;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
m_btn=new Button[9];
for(int i=0;i<9;i++)
{
m_btn[i]=(Button)this.findViewById(m_id[i]);
m_btn[i].setOnClickListener(new ButListener());
}

}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
class ButListener implements OnClickListener
{
public void onClick(View v)
{
for(int i=0;i<9;i++)
{
m_btn[i].setText(“Button”);
}
switch(v.getId())
{
case R.id.button1:
m_btn[0].setText(“01”);
break;
case R.id.button2:
m_btn[1].setText(“02”);
break;
case R.id.button3:
m_btn[2].setText(“03”);
break;
case R.id.button4:
m_btn[3].setText(“04”);
break;
case R.id.button5:
m_btn[4].setText(“05”);
break;
case R.id.button6:
m_btn[5].setText(“06”);
break;
case R.id.button7:
m_btn[6].setText(“07”);
break;
case R.id.button8:
m_btn[7].setText(“08”);
break;
case R.id.button9:
m_btn[8].setText(“09”);
break;
}
}
}
}