Using onSaveInstanceState with fragments in backstack?

android, android-fragments

Solution

It is possible that your member variables don't exist anymore because the `FragmentManager` in your `Activity` is dying with all of your fragments.

You need to override the method `onSaveInstanceState` of your `Activity` class as well, because you need to save the `Activity` state before you save the `Fragments` state.

As the documentation says:

There are many situations where a fragment may be mostly torn down (such as when placed on the back stack with no UI showing), but its state will not be saved until its owning activity actually needs to save its state.

UPDATE

In your `Activity` `onSaveInstanceState` and `onRestoreInstanceState`, try saving you `Fragment` references and then restore them with something like this:

public void onSaveInstanceState(Bundle outState){
    getFragmentManager().putFragment(outState, "myfragment", myfragment);
}
public void onRestoreInstanceState(Bundle inState){
    myFragment = getFragmentManager().getFragment(inState, "myfragment");
}

Tell me then if you had luck! :-)

Problem

I have fragments I keep in the backstack of FragmentManager. Every fragment state is saved for orientation changes with member variables, like this for example: ``` @Override public void onSaveInstanceState(Bundle outState) { super.onSaveInstanceState(outState); outState.putLong("userId", mUserId); outState.putString("username", mUsername); } ``` My problem is that if there is an orientation change, since every fragment in the backstack gets called via onSaveInstanceState, I get a null pointer exception because the member variables don't exist anymore. Any ideas on how to solve this?

Original source