savedInstanceState when restoring fragment from back stack

heero picture heero · Jun 20, 2012 · Viewed 56.3k times · Source

Can I use savedInstanceState() to save the state when removing a fragment, then restore the state when I pop the fragment off the back stack? When I restore the fragment from the back stack, savedInstanceState bundle is always null.

Right now, the app flow is: fragment created -> fragment removed (added to back stack) -> fragment restored from back stack (savedInstanceState bundle is null).

Here is the relevant code:

public void onActivityCreated(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    Bundle bundle = getArguments();
    Long playlistId = bundle.getLong(Constants.PLAYLIST_ID);
    int playlistItemId = bundle.getInt(Constants.PLAYLISTITEM_ID);

    if (savedInstanceState == null) {
       selectedVideoNumber = playlistItemId;
    } else {
       selectedVideoNumber = savedInstanceState.getInt("SELECTED_VIDEO");
    }
}

public void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        outState.putInt(Constants.SELECTED_VIDEO, selectedVideoNumber);
    }

I think the problem is that onSavedInstanceState() is never called when being removed and being added to back stack. If I cant use onsavedInstanceState(), is there another way to fix this?

Answer

Eric picture Eric · Jul 9, 2012

onSaveInstanceState is (unfortunately) not called in normal back-stack re-creation of a fragment. Check out http://developer.android.com/guide/components/fragments.html#Creating and the answer on How can I maintain fragment state when added to the back stack?