You need to add your Activity
as a OnBackStackChangedListener
using addOnBackStackChangedListener
.
Example:
@Override
protected void onCreate(Bundle savedInstanceState) {
.............
FragmentManager fragmentManager = getFragmentManager();
fragmentManager.addOnBackStackChangedListener(this);
fragmentManager.beginTransaction().add(R.id.frame_container,fragment, "First").addToBackStack(null).commit();
}