public class MyIntentService extends IntentService { 
public MyIntentService() { 
super("MyIntentService"); 
} 
@Override 
protected void onHandleIntent(Intent intent) { 
// IntentService会使用单独的线程来执行该方法的代码 
// 该方法内执行耗时任务，比如下载文件，此处只是让线程等待20秒 
long endTime = System.currentTimeMillis() + 20 * 1000; 
System.out.println("onStart"); 
while (System.currentTimeMillis() < endTime) { 
synchronized (this) { 
try { 
wait(endTime - System.currentTimeMillis()); 
} catch (InterruptedException e) { 
e.printStackTrace(); 
} 
} 
} 
System.out.println("----耗时任务执行完成---"); 
} 
}

public class MainActivity extends Activity implements OnClickListener { 
private Button startService; 
private Button stopService; 
@Override 
protected void onCreate(Bundle savedInstanceState) { 
super.onCreate(savedInstanceState); 
setContentView(R.layout.activity_main); 
startService = (Button) findViewById(R.id.start_service); 
stopService = (Button) findViewById(R.id.stop_service); 
startService.setOnClickListener(this); 
stopService.setOnClickListener(this); 
} 
@Override 
public void onClick(View v) { 
switch (v.getId()) { 
case R.id.start_service: 
Intent startIntent = new Intent(this, MyService.class); 
startService(startIntent); 
break; 
case R.id.stop_service: 
Intent stopIntent = new Intent(this, MyService.class); 
stopService(stopIntent); 
break; 
default: 
break; 
} 
}

<application 
android:allowBackup="true" 
android:icon="@drawable/ic_launcher" 
android:label="@string/app_name" 
android:theme="@style/AppTheme" > 
…… 
<service android:name="com.example.servicetest.MyService" > 
</service> 
</application>

public class LocalService extends Service { 
// Binder given to clients 
private final IBinder mBinder = new LocalBinder(); 
// Random number generator 
private final Random mGenerator = new Random(); 
public class LocalBinder extends Binder { 
LocalService getService() { 
// 返回本service的实例到客户端，于是客户端可以调用本service的公开方法 
return LocalService.this; 
} 
} 
@Override 
public IBinder onBind(Intent intent) { 
return mBinder; 
} 
/**客户端所要调用的方法*/ 
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(); 
// 绑定到类LocalService的实例 
Intent intent = new Intent(this, LocalService.class); 
bindService(intent, mConnection, Context.BIND_AUTO_CREATE); 
} 
@Override 
protected void onStop() { 
super.onStop(); 
// 从service解除绑定 
if (mBound) { 
unbindService(mConnection); 
mBound = false; 
} 
} 
/** 当按钮按下时调用(在layout文件中定义的button并用android:onClick 属性指定响应到本方法) */ 
public void onButtonClick(View v) { 
if (mBound) { 
// 调用LocalService的一个方法 
// 然而，如果这个调用中有挂起操作，那么这个请求应发 
// 生在另一个线程来避免拉低activity的性能． 
int num = mService.getRandomNumber(); 
Toast.makeText(this, "number: " + num, Toast.LENGTH_SHORT).show(); 
} 
} 
/** 定义service绑定的回调，传给bindService() 的*/ 
private ServiceConnection mConnection = new ServiceConnection() { 
@Override 
public void onServiceConnected(ComponentName className, 
IBinder service) { 
//我们已经绑定到了LocalService，把IBinder进行强制类型转换并且获取LocalService实例． 
LocalBinder binder = (LocalBinder) service; 
mService = binder.getService(); 
mBound = true; 
} 
@Override 
public void onServiceDisconnected(ComponentName arg0) { 
mBound = false; 
} 
}; 
}

public class MyIntentService extends IntentService { 
public MyIntentService() { 
super("MyIntentService"); 
} 
@Override 
protected void onHandleIntent(Intent intent) { 
// IntentService会使用单独的线程来执行该方法的代码 
// 该方法内执行耗时任务，比如下载文件，此处只是让线程等待20秒 
long endTime = System.currentTimeMillis() + 20 * 1000; 
System.out.println("onStart"); 
while (System.currentTimeMillis() < endTime) { 
synchronized (this) { 
try { 
wait(endTime - System.currentTimeMillis()); 
} catch (InterruptedException e) { 
e.printStackTrace(); 
} 
} 
} 
System.out.println("----耗时任务执行完成---"); 
} 
}

public void startIntentService(View source) { 
// 创建需要启动的IntentService的Intent 
Intent intent = new Intent(this, MyIntentService.class); 
startService(intent); 
}