Why is my onResume being called twice?

Huy T picture Huy T · Apr 16, 2013 · Viewed 34k times · Source

Basically, this is what I'm doing

1) Set AlarmManager to execute BroadcastReceiver (BCR)

Intent intent = new Intent(m_Context, BCR.class);  
intent.putExtras(extras);  
PendingIntent pendingIntent = PendingIntent.getBroadcast(m_Context, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);  
AlarmManager am = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
am.set(AlarmManager.RTC_WAKEUP, StartTime, pendingIntent)  

2) Start MyActivity from BCR

@Override  
public void onReceive(Context context, Intent intent) {  
    Intent newIntent = new Intent(context, MyActivity.class);
    newIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_SINGLE_TOP);  
    context.startActivity(newIntent);  
}

3) Have MyActivity turn on the screen if its not on

@Override  
public void onCreate(Bundle savedInstanceState) {  
    super.onCreate(savedInstanceState); 
    getWindow().addFlags(LayoutParams.FLAG_DISMISS_KEYGUARD);
    getWindow().addFlags(LayoutParams.FLAG_SHOW_WHEN_LOCKED);
    getWindow().addFlags(LayoutParams.FLAG_TURN_SCREEN_ON);
    setContentView(R.layout.myactivity);  
} 

@Overide  
protected void onNewIntent(Intent intent) {  
    super.onNewIntent(intent);  
}  

For some reason, I notice that right when MyActivity is opened, it's flow goes like:

onCreate/onNewIntent -> onResume -> onPause -> onResume

I'm not sure why it does an onPause right away. I notice this only happens when the screened is being turned on by the flags. Does anyone know why this happens? Is there any way this behavior can be prevented?

Answer

ainesophaur picture ainesophaur · Nov 4, 2013

Just in case anyone else runs into this, I seem to notice this behaviour only when I inflate fragments inside of an activity via XML layout. I don't know if this behaviour also happens with the compatibility library version of Fragments (I'm using android.app.Fragment)

It seems the activity will call Activity#onResume once before calling Fragment#onResume to any added Fragments, and then will call Activity#onResume again.

  1. Activity:onCreate
  2. Fragment:onAttach
  3. Activity:onAttachFragments
  4. Fragment:onCreate
  5. Activity: onStart
  6. Activity: onResume
  7. Fragment: onResume
  8. Activity: onResume