Why is Android O failing with “does not belong to this FragmentManager!”

Question

I have migrated my application to Android O in Android Studio 3

Running on an Android O emulator all my dialogFragments now fail with :-

java.lang.I         


        

Answer 1

Use below solution and you do not need to worry about which fragment managers you are dealing with,

Assuming that you must have used a BaseFragment.

First create an interface:

public interface OnRequestUpdateListener {
void onRequestUpdate(final int requestCode, final Intent data);

void setRequestFragment(final BaseFragment requestFragment, int requestCode);

BaseFragment getRequestFragment();

int getRequestCode();

}

Implement that interface in your BaseFragment

public class BaseFragment extends Fragment implements OnRequestUpdateListener {
private BaseFragment requestFragment;

private int requestCode;

@Override
public void onRequestUpdate(int requestCode, Intent data) {
 // you can implement your logic the same way you do in onActivityResult
}

@Override
public void setRequestFragment(BaseFragment requestFragment, int requestCode) {
    this.requestFragment = requestFragment;
    this.requestCode = requestCode;
}

@Override
public BaseFragment getRequestFragment() {
    return requestFragment;
}

@Override
public int getRequestCode() {
    return requestCode;
}

}

Then, replace the setTargetFragment with setRequestFragment and replace getTargetFragment with getRequestFragment.

Here, you could also user onRequestUpdate in place of onActivityResult.

This is a custom solution without bothering about the which fragment manager you are using.

Using getFragmentManager() instead of getChildFragmentManager() would also work but it affects getParentFragment(). If you do not use a getChildFragmentManager() for nested fragment then you will not be able the get the parent fragment by using getParentFragment() in child/nested fragment.

Answer 2

I had the same problem, definitely an android bug. It happens when you are showing a fragment from another fragment using it as target. As workaround you can use:

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O)
    getActivity().getFragmentManager().beginTransaction().add(dialogFrag, "dialog").commit();
else
    getChildFragmentManager().beginTransaction().add(dialogFrag,"dialog").commit();