在IntentService中註冊的監聽器只接收一次通知

Question

我正在寫一個簡單的應用程序來跟蹤我的手機信號強度較差的時段。我這樣做是使用IntentService，該監聽PhoneStateListener.LISTEN_SIGNAL_STRENGTHS如下：

public class PoorSignalIntentService extends IntentService { 

    private TelephonyManager mTelephonyManager; 
    private PhoneStateListener mPhoneStateListener; 
    public PoorSignalIntentService() { 
     super("PoorSignalIntentService"); 
    } 

    @Override 
    protected void onHandleIntent(Intent intent) { 
     mPhoneStateListener = new PhoneStateListener(){ 
      @Override 
      public void onSignalStrengthsChanged(SignalStrength signalStrength) { 
       doSomething(signalStrength); 
       super.onSignalStrengthsChanged(signalStrength); 
      } 

      @Override 
      public void onServiceStateChanged(ServiceState serviceState) { 
       doSomething(serviceState); 
       super.onServiceStateChanged(serviceState); 
      } 
     }; 

     mTelephonyManager = (TelephonyManager)getSystemService(TELEPHONY_SERVICE); 
     mTelephonyManager.listen(mPhoneStateListener, PhoneStateListener.LISTEN_SIGNAL_STRENGTHS|PhoneStateListener.LISTEN_SERVICE_STATE); 

    } 

    private void doSomething(SignalStrength signalStrength){ 
     Log.d(TAG, "Signal Strength changed! New strength = "+signalStrength.getGsmSignalStrength()); 
    } 

    private void doSomething(ServiceState serviceState){ 
     Log.d(TAG, "Service State changed! New state = "+serviceState.getState()); 
    } 

    @Override 
    public void onDestroy() { 
     Log.d(TAG, "Shutting down the IntentService"); 
     mTelephonyManager.listen(mPhoneStateListener, PhoneStateListener.LISTEN_NONE); 
     super.onDestroy(); 
    } 
} 

但是，我看到後收到的第一信號強度變更通知，onDestroy()被稱爲（據推測，IntentService電話stopSelf()）。

此問題不限於PhoneStateListener。我還有一個簡單的應用程序，它使用了接近傳感器這樣的：

@Override 
    protected void onHandleIntent(Intent intent){ 
     mSensorManager.registerListener(this, mProximity, SensorManager.SENSOR_DELAY_NORMAL); 
    } 

在這種情況下，也只被告知第一鄰近的變化，在這之後Service停止本身。

那麼，在Service中註冊類似聽衆的模式是什麼？

Answer 1

好的，我找到了解決方案。我的錯。我應該使用Service而不是IntentService，因爲後者在處理它在onHandleIntent()中收到的意圖後調用stopSelf()。

這裏的延伸Service工作代碼：

public class PoorSignalService extends Service { 

    private TelephonyManager mTelephonyManager; 
    private PhoneStateListener mPhoneStateListener; 


    @Override 
    public IBinder onBind(Intent intent) { 
     // We don't want to bind; return null. 
     return null; 
    } 


    @Override 
    public void onCreate() { 
     mTelephonyManager = (TelephonyManager)getSystemService(TELEPHONY_SERVICE); 
     mPhoneStateListener = new PhoneStateListener(){ 
      @Override 
      public void onSignalStrengthsChanged(SignalStrength signalStrength) { 
       doSomething(signalStrength); 
       super.onSignalStrengthsChanged(signalStrength); 
      } 

      @Override 
      public void onServiceStateChanged(ServiceState serviceState) { 
       doSomething(serviceState); 
       super.onServiceStateChanged(serviceState); 
      } 
     }; 
     super.onCreate(); 
    } 

    @Override 
    public int onStartCommand(Intent intent, int flags, int startId) { 
     //Register the listener here. 
     mTelephonyManager.listen(mPhoneStateListener, PhoneStateListener.LISTEN_SIGNAL_STRENGTHS|PhoneStateListener.LISTEN_SERVICE_STATE); 
     return super.onStartCommand(intent, flags, startId); 
    } 


    private void doSomething(SignalStrength signalStrength){ 
     Log.d(TAG, "Signal Strength changed! New strength = "+signalStrength.getGsmSignalStrength()); 
    } 

    private void doSomething(ServiceState serviceState){ 
     Log.d(TAG, "Service State changed! New state = "+serviceState.getState()); 
    } 

    @Override 
    public void onDestroy() { 
     Log.d(TAG, "Shutting down the Service"); 
     mTelephonyManager.listen(mPhoneStateListener, PhoneStateListener.LISTEN_NONE); 
     super.onDestroy(); 
    } 
}