Android - how to differentiate activity restart from a “normal” start

Question

I'm trying to distinguish if an activity is destroyed then restarted vs. when it's started via standard startActivity call. What's the best way to distinguish this? I need to track a counter, and the counter should not be incremented when the app has been destroyed and restarted. I tried using putExtra(String, String), but the value returned is the same regardless.

Answer 1

You could try using a flag isSavedInstanceState. Set this flag to false in onResume. Set this flag to true in onSaveInstanceState. Check this flag in onStop.

@Override
protected void onStop(){
   super.onStop();
   if (!isSavedInstanceState){ // this is a HARD KILL, write to prefs
       SharedPreferences prefs = getPreferences(MODE_PRIVATE);
       SharedPreferences.Editor editor = prefs.edit();
       editor.putYourCounterIncrementHere
       editor.commit();
       Log.d(TAG,"savedPrefs");
   }
   else {
       Log.d(TAG,"DidNotSavePrefs");
   }
   Log.d(TAG,"onStop");
}

This will increment your counter on a hard kill. You could check the bundle in onCreate for a null bundle if you want, but I have not fully tested that logic.