<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:tools="http://schemas.android.com/tools"
 android:layout_width="fill_parent"
 android:layout_height="fill_parent"
 android:orientation="vertical" >

 <Button
 android:id="@+id/btnYellow"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:text="黃色"
 android:textColor="#fff"
 />
 <Button
 android:id="@+id/btnBlue"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:text="藍(lán)色"
 android:textColor="#fff"
 />

</LinearLayout>

<?xml version="1.0" encoding="UTF-8"?>
<resources>
 <color name="yellow">#ffee55</color>
 <color name="blue">#0000ff</color>
</resources>

package com.example.ch03;

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

public class MainActivity extends Activity {

 //聲明兩個(gè)按鈕
 Button btnYellow;
 Button btnBlue;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);
 //根據(jù)Id找到界面中的兩個(gè)按鈕組件
 btnYellow=(Button)this.findViewById(R.id.btnYellow);
 btnBlue=(Button)this.findViewById(R.id.btnBlue);

 //注冊(cè)監(jiān)聽器
 btnYellow.setOnClickListener(new OnClickListener(){
  public void onClick(View v){
  //設(shè)置背景顏色為黃色
  getWindow().setBackgroundDrawableResource(R.color.yellow);
  }
 });

 btnBlue.setOnClickListener(new OnClickListener(){
  public void onClick(View v){
  //設(shè)置背景顏色為藍(lán)色
  getWindow().setBackgroundDrawableResource(R.color.blue);
  }
 });
 }
}