Android: onSaveInstanceState not being called from activity

I have an Activity A which calls Activity B. In Activity B, when i click on a button, finish() is called, which in turn calls onDestroy() of Activity B and returns to activity A.

According to android documentation, Before onDestroy is called, onSaveInstanceState(Bundle bundle) will be called, where i do the following.

@Override
    public void onSaveInstanceState(Bundle outState) {

        super.onSaveInstanceState(outState);
        System.out.println("Saving webview state");
        Log.d(TAG, "In onsave");
        wv.saveState(outState);

    }

and the next time Activity B is started from Activity A,

in the oncreate(), i do the following:

onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);

if(savedInstanceState != null){
//restore webview
}else {
// code
}
}

However, before calling onDestroy in Activity B, The onSaveInstanceState method is never called. any help on this will be greatly appreciated.

EDIT: if this is not possible. Please let me know if there is a way to store webview state

Solution 1:

I had a similar situation. It was clearly a dev bug. I've overridden the wrong method:

public void onSaveInstanceState(Bundle outState, 
                                PersistableBundle outPersistentState)

Instead a correct one:

protected void onSaveInstanceState(Bundle outState)

Solution 2:

Please notice that onRestoreInstanceState() is called when activity is recreated but only if:

it was killed by the OS. "Such situation happen when:

• orientation of the device changes (your activity is destroyed and recreated)
• there is another activity in front of yours and at some point the OS kills your activity in order to free memory (for example). Next time when you start your activity onRestoreInstanceState() will be called."

So if you are in your activity and you hit Back button on the device, your activity is finish()ed and next time you start your app it is started again (it sounds like re-created, isn't it?) but this time without saved state because you intentionally exited it when you hit Back button.

Solution 3:

See the doc here: http://developer.android.com/reference/android/app/Activity.html

Note that it is important to save persistent data in onPause() instead of onSaveInstanceState(Bundle) because the latter is not part of the lifecycle callbacks, so will not be called in every situation as described in its documentation.

The documentation of onSaveInstanceState method says,

Do not confuse this method with activity lifecycle callbacks such as onPause(), which is always called when an activity is being placed in the background or on its way to destruction, or onStop() which is called before destruction. One example of when onPause() and onStop() is called and not this method is when a user navigates back from activity B to activity A: there is no need to call onSaveInstanceState(Bundle) on B because that particular instance will never be restored, so the system avoids calling it. An example when onPause() is called and not onSaveInstanceState(Bundle) is when activity B is launched in front of activity A: the system may avoid calling onSaveInstanceState(Bundle) on activity A if it isn't killed during the lifetime of B since the state of the user interface of A will stay intact.

try this:

@Override
public void onPause(){
   System.out.println("Saving webview state");
    Log.d(TAG, "In onsave");
    wv.saveState(outState);
    super.onPause();

}

and
@Override
 public void onResume(){
     //restore webview
 }

I am not sure what is the purpose of that if statement, but try this and see what happens.