Question

I am experimenting with using fragments in my application. I am trying to find a way to store data used by a fragment when I switch my application to the other fragment. My code for my second fragment is found below. When switching to and from this fragment I am using add and remove fragment. This is because when I was using replace, I was having trouble. Whenever I switch to my other fragment, and back to this one, count is not stored. How do I actually store count so I can come back to it when my fragment opens back up?

public class BasicFragment2 extends Fragment {

public int count = 0;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    if (savedInstanceState != null){
        count = savedInstanceState.getInt("Integer");
    }

    View view = inflater.inflate(R.layout.fragment_basic_2, container, false);

    Button button = (Button) view.findViewById(R.id.button2);

    // A simple OnClickListener for our button. You can see here how a Fragment can encapsulate
    // logic and views to build out re-usable Activity components.
    button.setOnClickListener(new OnClickListener() {

        public void onClick(View v) {
            Activity activity = getActivity();
            count++;

            if (activity != null) {
                Toast.makeText(activity, "This is not a fragment...Yes it is " + count, Toast.LENGTH_LONG).show();
            }
        }

    });

    return view;
}

public void onSaveInstanceState(Bundle outState){
    outState.putInt("Integer",count);
    super.onSaveInstanceState(outState);
}

}

Answer 1

Try overriding onSaveInstanceState in your Activity class and save the count value there. Because as per google docs:

Note however: this method may be called at any time before
onDestroy(). 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.