Android Fragment implements dialog fragment listener "null pointer exception"

Question

I have an Activity A. And in stepperLayout of this activity I use Fragment B. I call dialogFragment C from Fragment B. Than on DialogFragment C i call listenerInterface method but listener Interface is null. So there was a null pointer exception. Activity A not implement the interface. Only fragment B implements it.

 My Fragment B

 dialogFragmentC = DialogFragmentC .newInstance();
 dialogFragmentC .show(getFragmentManager(), "");

My DialogFragment C

 @Override
    public void onAttach(Context context) {
        super.onAttach(context);
        try {
            this.listener = (DialogFragmentListener) context;
        } catch (Exception e) {
            Timber.i(e);
        }
    }

score 0 · Answer 1 · answered Jan 12 '19 at 13:51

Since you launch a dialog fragment from a fragment, the traditional way won't work.

Solution 1:

Use child fragment manager to launch: dialogFragmentC.show(getChildFragmentManager(), ""); and then check parent fragment: this.listener = (DialogFragmentListener) getParentFragment();

Solution 2:

Use target fragment: Android - getTargetFragment and setTargetFragment - What are they used for. Set the target fragment of your dialogFragmentC to FragmentB when you create dialogFragmentC and use getTargetFragment in the dialogFragmentC to get the listener.

Android Fragment implements dialog fragment listener "null pointer exception"

1 Answers1