BroadcastReceiver Vs WakefulBroadcastReceiver

Question

Czy ktoś może wyjaśnić, jaka jest różnica między BroadcastReceiver i WakefulBroadcastReceiver?

W jakich sytuacjach będziemy musieli korzystać z każdej klasy Odbiornika?

Answer 1

Istnieje tylko jedna różnica między BroadcastReceiver i WakefulBroadcastReceiver.

Po odebraniu transmisji wewnątrz onReceive() metodzie

Załóżmy,

BroadcastReceiver:

• Jest nie gwarantuje że CPU zasnąć jeśli zainicjować niektóre długotrwały proces. Procesor może natychmiast powrócić do trybu uśpienia.

WakefulBroadcastReceiver:

• Jest gwarantowana że CPU zasnąć aż ogień completeWakefulIntent.

Przykład:

Tutaj, po odebraniu transmisji, zaczynają usługi, jak używasz WakefulBroadcastReceiver będzie trzymać wakelock i nie pozwolę snu procesora aż do zakończenia prac w obrębie serwisu i ogień completeWakefulIntent

Kod:

public class SimpleWakefulReceiver extends WakefulBroadcastReceiver { 
    @Override 
    public void onReceive(Context context, Intent intent) { 
     // This is the Intent to deliver to our service. 
     Intent service = new Intent(context, SimpleWakefulService.class); 

     // Start the service, keeping the device awake while it is launching. 
     Log.i("SimpleWakefulReceiver", "Starting service @ " + SystemClock.elapsedRealtime()); 
     startWakefulService(context, service); 
    } 
} 

class SimpleWakefulService extends IntentService { 
    public SimpleWakefulService() { 
     super("SimpleWakefulService"); 
    } 

    @Override 
    protected void onHandleIntent(Intent intent) { 
     // At this point SimpleWakefulReceiver is still holding a wake lock 
     // for us. We can do whatever we need to here and then tell it that 
     // it can release the wakelock. This sample just does some slow work, 
     // but more complicated implementations could take their own wake 
     // lock here before releasing the receiver's. 
     // 
     // Note that when using this approach you should be aware that if your 
     // service gets killed and restarted while in the middle of such work 
     // (so the Intent gets re-delivered to perform the work again), it will 
     // at that point no longer be holding a wake lock since we are depending 
     // on SimpleWakefulReceiver to that for us. If this is a concern, you can 
     // acquire a separate wake lock here. 
     for (int i=0; i<5; i++) { 
      Log.i("SimpleWakefulReceiver", "Running service " + (i+1) 
        + "/5 @ " + SystemClock.elapsedRealtime()); 
      try { 
       Thread.sleep(5000); 
      } catch (InterruptedException e) { 
      } 
     } 
     Log.i("SimpleWakefulReceiver", "Completed service @ " + SystemClock.elapsedRealtime()); 
     SimpleWakefulReceiver.completeWakefulIntent(intent); 
    } 
}