public class LocalService extends Service { 
  // 實(shí)例化自定義的Binder類 
  private final IBinder mBinder = new LocalBinder(); 
  // 隨機(jī)數(shù)的生成器 
  private final Random mGenerator = new Random(); 
 
  /** 
   * 自定義的Binder類，這個(gè)是一個(gè)內(nèi)部類，所以可以知道其外圍類的對(duì)象，通過這個(gè)類，讓Activity知道其Service的對(duì)象 
   */ 
  public class LocalBinder extends Binder { 
    LocalService getService() { 
      // 返回Activity所關(guān)聯(lián)的Service對(duì)象，這樣在Activity里，就可調(diào)用Service里的一些公用方法和公用屬性 
      return LocalService.this; 
    } 
  } 
 
  @Override 
  public IBinder onBind(Intent intent) { 
    return mBinder; 
  } 
 
  /** public方法，Activity可以進(jìn)行調(diào)用 */ 
  public int getRandomNumber() { 
   return mGenerator.nextInt(100); 
  } 
} 
 

public class BindingActivity extends Activity { 
  LocalService mService; 
  boolean mBound = false; 
 
  @Override 
  protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.main); 
  } 
 
  @Override 
  protected void onStart() { 
    super.onStart(); 
    // 綁定Service，綁定后就會(huì)調(diào)用mConnetion里的onServiceConnected方法 
    Intent intent = new Intent(this, LocalService.class); 
    bindService(intent, mConnection, Context.BIND_AUTO_CREATE); 
  } 
 
  @Override 
  protected void onStop() { 
    super.onStop(); 
    // 解綁Service，這樣可以節(jié)約內(nèi)存 
    if (mBound) { 
      unbindService(mConnection); 
      mBound = false; 
    } 
  } 
 
  /** 用戶點(diǎn)擊button，就讀取Service里的隨機(jī)數(shù) */ 
  public void onButtonClick(View v) { 
    if (mBound) { 
      // 用Service的對(duì)象，去讀取隨機(jī)數(shù) 
      int num = mService.getRandomNumber(); 
      Toast.makeText(this, "number: " + num, Toast.LENGTH_SHORT).show(); 
    } 
  } 
 
  /** 定交ServiceConnection，用于綁定Service的*/ 
  private ServiceConnection mConnection = new ServiceConnection() { 
 
    @Override 
    public void onServiceConnected(ComponentName className, 
        IBinder service) { 
      // 已經(jīng)綁定了LocalService，強(qiáng)轉(zhuǎn)IBinder對(duì)象，調(diào)用方法得到LocalService對(duì)象 
      LocalBinder binder = (LocalBinder) service; 
      mService = binder.getService(); 
      mBound = true; 
    } 
 
    @Override 
    public void onServiceDisconnected(ComponentName arg0) { 
      mBound = false; 
    } 
  }; 
} 

 public class MessengerService extends Service { 
  /** 用于Handler里的消息類型 */ 
  static final int MSG_SAY_HELLO = 1; 
 
  /** 
   * 在Service處理Activity傳過來消息的Handler 
   */ 
  class IncomingHandler extends Handler { 
    @Override 
    public void handleMessage(Message msg) { 
      switch (msg.what) { 
        case MSG_SAY_HELLO: 
          Toast.makeText(getApplicationContext(), "hello!", Toast.LENGTH_SHORT).show(); 
          break; 
        default: 
          super.handleMessage(msg); 
      } 
    } 
  } 
 
  /** 
   * 這個(gè)Messenger可以關(guān)聯(lián)到Service里的Handler，Activity用這個(gè)對(duì)象發(fā)送Message給Service，Service通過Handler進(jìn)行處理。 
   */ 
  final Messenger mMessenger = new Messenger(new IncomingHandler()); 
 
  /** 
   * 當(dāng)Activity綁定Service的時(shí)候，通過這個(gè)方法返回一個(gè)IBinder，Activity用這個(gè)IBinder創(chuàng)建出的Messenger，就可以與Service的Handler進(jìn)行通信了 
   */ 
  @Override 
  public IBinder onBind(Intent intent) { 
    Toast.makeText(getApplicationContext(), "binding", Toast.LENGTH_SHORT).show(); 
    return mMessenger.getBinder(); 
  } 
} 
 

public class ActivityMessenger extends Activity { 
  /** 向Service發(fā)送Message的Messenger對(duì)象 */ 
  Messenger mService = null; 
 
  /** 判斷有沒有綁定Service */ 
  boolean mBound; 
 
  private ServiceConnection mConnection = new ServiceConnection() { 
    public void onServiceConnected(ComponentName className, IBinder service) { 
      // Activity已經(jīng)綁定了Service 
      // 通過參數(shù)service來創(chuàng)建Messenger對(duì)象，這個(gè)對(duì)象可以向Service發(fā)送Message，與Service進(jìn)行通信 
      mService = new Messenger(service); 
      mBound = true; 
    } 
 
    public void onServiceDisconnected(ComponentName className) { 
      mService = null; 
      mBound = false; 
    } 
  }; 
 
  public void sayHello(View v) { 
    if (!mBound) return; 
    // 向Service發(fā)送一個(gè)Message 
    Message msg = Message.obtain(null, MessengerService.MSG_SAY_HELLO, 0, 0); 
    try { 
      mService.send(msg); 
    } catch (RemoteException e) { 
      e.printStackTrace(); 
    } 
  } 
 
  @Override 
  protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.main); 
  } 
 
  @Override 
  protected void onStart() { 
    super.onStart(); 
    // 綁定Service 
    bindService(new Intent(this, MessengerService.class), mConnection, 
      Context.BIND_AUTO_CREATE); 
  } 
 
  @Override 
  protected void onStop() { 
    super.onStop(); 
    // 解綁 
    if (mBound) { 
      unbindService(mConnection); 
      mBound = false; 
    } 
  } 
}