Question

Suppose I have two fragments: firstFragment, and secondFragment

I know I can replace a fragment by:

fragmentTransaction.replace(R.id.fragment_placeholder, firstFragment);
fragmentTransaction.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
fragmentTransaction.commit();

Like the above code shows, I did not add the above firstFragment to back stack.

Then, I replace with the secondFragment, But this time, I add the secondFragment to back stack:

fragmentTransaction.replace(R.id.fragment_placeholder, secondFragment);
fragmentTransaction.addToBackStack(null); //add to back stack
fragmentTransaction.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
fragmentTransaction.commit();

On my mobile screen, it is now showing the secondFragment.

My question is, how can I remove the firstFragment which is not added to back stack ?

Answer 1

After detaching the fragment the fragment will be destroyed. To make sure wether your fragment is still in the layout you can use the “Hierarchy Viewer” perspective. To use the hierarchy viewer you have to use an emulator or a rooted device though. (http://developer.android.com/guide/topics/fundamentals/fragments.html#Creating)

However if you use the android-support-v4.jar to support 1.6 and higher make sure you don’t define any fragments in a xml-layout. The fragments in the xml-layout can’t be removed when you use android-support-v4.jar. Just do it, if you use fragments which will be displayed all the time (e.g. navigation)

Edit: Replace should remove the firstfragment as well. Replace will replace all children inside the container with the given fragment.