Remove old Fragment from fragment manager

Question

I'm trying to learn how to use Fragments in android. I'm trying to remove old fragment when new fragment is calling in android.

Answer 1

You need to find reference of existing Fragment and remove that fragment using below code. You need add/commit fragment using one tag ex. "TAG_FRAGMENT".

Fragment fragment = getSupportFragmentManager().findFragmentByTag(TAG_FRAGMENT);
if(fragment != null)
    getSupportFragmentManager().beginTransaction().remove(fragment).commit();

That is it.

Answer 2

I had the same issue. I came up with a simple solution. Use fragment .replace instead of fragment .add. Replacing fragment doing the same thing as adding fragment and then removing it manually.

getFragmentManager().beginTransaction().replace(fragment).commit();

instead of

getFragmentManager().beginTransaction().add(fragment).commit();

Answer 3

I had the same issue to remove old fragments. I ended up clearing the layout that contained the fragments.

LinearLayout layout = (LinearLayout) a.findViewById(R.id.layoutDeviceList);
layout.removeAllViewsInLayout();
FragmentTransaction ft = getFragmentManager().beginTransaction();
...

I do not know if this creates leaks, but it works for me.

Answer 4

Probably you instance old fragment it is keeping a reference. See this interesting article Memory leaks in Android — identify, treat and avoid

If you use addToBackStack, this keeps a reference to instance fragment avoiding to Garbage Collector erase the instance. The instance remains in fragments list in fragment manager. You can see the list by

ArrayList<Fragment> fragmentList = fragmentManager.getFragments();

The next code is not the best solution (because don´t remove the old fragment instance in order to avoid memory leaks) but removes the old fragment from fragmentManger fragment list

int index = fragmentManager.getFragments().indexOf(oldFragment);
fragmentManager.getFragments().set(index, null);

You cannot remove the entry in the arrayList because apparenly FragmentManager works with index ArrayList to get fragment.

I usually use this code for working with fragmentManager

public void replaceFragment(Fragment fragment, Bundle bundle) {

    if (bundle != null)
        fragment.setArguments(bundle);

    FragmentManager fragmentManager = getSupportFragmentManager();
    FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
    Fragment oldFragment = fragmentManager.findFragmentByTag(fragment.getClass().getName());

    //if oldFragment already exits in fragmentManager use it
    if (oldFragment != null) {
        fragment = oldFragment;
    }

    fragmentTransaction.replace(R.id.frame_content_main, fragment, fragment.getClass().getName());

    fragmentTransaction.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);

    fragmentTransaction.commit();
}

Answer 5

I had issue with fragment onBackPress. I didn't want to return to old fragments.

This solution worked for me to remove old fragments from fragment manager :

FragmentManager fm = getSupportFragmentManager();
fm.popBackStack(null, FragmentManager.POP_BACK_STACK_INCLUSIVE);

You can also use an if block like this :

FragmentManager fm = getSupportFragmentManager();

if (fm.getBackStackEntryCount() > 0) {
    fm.popBackStack(null, FragmentManager.POP_BACK_STACK_INCLUSIVE);
}

Answer 6

In Kotlin

  val fragList  = f.supportFragmentManager.fragments
    for (fragment in fragList) {
        f.supportFragmentManager.beginTransaction().remove(fragment).commit()
    }

Answer 7

I was facing the same error with few views so I set the visibility of reductant views as GONE. This method solved my issue as charm.

<View>.setVisibility(View.GONE);