public class BindService extends Service
{
  private int count;
  private boolean quit;
  // 定义onBinder方法所返回的对象
  private MyBinder binder = new MyBinder();
  // 通过继承Binder来实现IBinder类
  public class MyBinder extends Binder
  {
    public int getCount()
    {
      // 获取Service的运行状态：count
      return count;
    }
  }
  // 必须实现的方法
  @Override
  public IBinder onBind(Intent intent)
  {
    System.out.println("Service is Binded");
    // 返回IBinder对象
    return binder;
  }
  // Service被创建时回调该方法。
  @Override
  public void onCreate()
  {
    super.onCreate();
    System.out.println("Service is Created");
    // 启动一条线程、动态地修改count状态值
    new Thread()
    {
      @Override
      public void run()
      {
        while (!quit)
        {
          try
          {
            Thread.sleep(1000);
          }
          catch (InterruptedException e)
          {
          }
          count++;
        }
      }
    }.start();    
  }
  // Service被断开连接时回调该方法
  @Override
  public boolean onUnbind(Intent intent)
  {
    System.out.println("Service is Unbinded");
    return true;
  }
  // Service被关闭之前回调。
  @Override
  public void onDestroy()
  {
    super.onDestroy();
    this.quit = true;
    System.out.println("Service is Destroyed");
  }
  
  @Override
  public void onRebind(Intent intent) 
  {
    super.onRebind(intent);
    this.quit = true;
    System.out.println("Service is ReBinded");
  }  
}

public class MainActivity extends Activity
{
  Button startService_bnt , bindService_bnt;
  // 保持所启动的Service的IBinder对象
  BindService.MyBinder binder;
 
  @Override
  public void onCreate(Bundle savedInstanceState)
  {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
 
    startService_bnt = (Button) findViewById(R.id.start_bnt);
    bindService_bnt = (Button) findViewById(R.id.bind_bnt);
 
    //创建启动Service的Intent
     Intent intent = new Intent(this,BindService.class);
 
     startService_bnt.setOnClickListener(new OnClickListener()
    {
      @Override
      public void onClick(View source)
      {
        //绑定指定Serivce
        startService(intent);
      }
    });  
    
    bindService_bnt.setOnClickListener(new OnClickListener()
    {
      @Override
      public void onClick(View source)
      {
        //绑定指定Serivce
        bindService(intent , conn , Service.BIND_AUTO_CREATE);  
        
        Toast.makeText(MainActivity.this
          , "Serivce的count值为：" + binder.getCount()
          , 4000)
          .show();
      }
    });
 
 
  }
  
    // 定义一个ServiceConnection对象
  private ServiceConnection conn = new ServiceConnection()
  {
    // 当该Activity与Service连接成功时回调该方法
    @Override
    public void onServiceConnected(ComponentName name
      , IBinder service)
    {
      System.out.println("--Service Connected--");
      // 获取Service的onBind方法所返回的MyBinder对象
      binder = (BindService.MyBinder) service;
    }
    // 当该Activity与Service断开连接时回调该方法
    @Override
    public void onServiceDisconnected(ComponentName name)
    {
      System.out.println("--Service Disconnected--");      
    }
  };
}

 startService（intent），
 bindService(Intent service，ServiceConnection conn,int flags)，
 

// 定义一个ServiceConnection对象
  private ServiceConnection conn = new ServiceConnection()
  {
    // 当该Activity与Service连接成功时回调该方法
    @Override
    public void onServiceConnected(ComponentName name
      , IBinder service)
    {
      System.out.println("--Service Connected--");
      // 获取Service的onBind方法所返回的MyBinder对象
      binder = (BindService.MyBinder) service;
    }
    // 当该Activity与Service断开连接时回调该方法
    @Override
    public void onServiceDisconnected(ComponentName name)
    {
      System.out.println("--Service Disconnected--");      
    }
  };

@Override
  public IBinder onBind(Intent intent)
  {
    System.out.println("Service is Binded");
    // 返回IBinder对象
    return binder;
  }

// 通过继承Binder来实现IBinder类
  public class MyBinder extends Binder
  {
    public int getCount()
    {
      // 获取Service的运行状态：count
      return count;
    }
  }