IllegalStateException: Can't change container ID of Fragment

Question

Android platform: 3.1

I am trying to move a fragment from a container A to a container B. Here follows the code to accomplish this:

private void rea         


        

Answer 1

My solution to this problem is to re-create the fragment while keeping its state:

FragmentTransaction ft = mFragmentManager.beginTransaction();
ft.remove(old);
Fragment newInstance = recreateFragment(old);
ft.add(R.id.new_container, newInstance);
ft.commit();

With the following helper function:

private Fragment recreateFragment(Fragment f)
    {
        try {
            Fragment.SavedState savedState = mFragmentManager.saveFragmentInstanceState(f);

            Fragment newInstance = f.getClass().newInstance();
            newInstance.setInitialSavedState(savedState);

            return newInstance;
        }
        catch (Exception e) // InstantiationException, IllegalAccessException
        {
            throw new RuntimeException("Cannot reinstantiate fragment " + f.getClass().getName(), e);
        }
    }

It works for me, at least with the latest support library (r11), although I didn't test much yet.

The extra cost is to instantiate the fragment twice.