Handling Click Events in Nested Fragments Causes IllegalStateException in Android 12
I'm stuck trying to I am experiencing an `IllegalStateException` when trying to handle click events in nested fragments in my Android application targeting API level 31 (Android 12)..... The setup involves a parent fragment that contains a child fragment, and I'm trying to pass click events from the child back to the parent. However, when I try to call the parent's function from the child's click listener, I get the following error: ``` java.lang.IllegalStateException: Fragment {some_fragment_id} not attached to Activity ``` Here's a simplified version of the code: **ParentFragment.java**: ```java public class ParentFragment extends Fragment { @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View view = inflater.inflate(R.layout.fragment_parent, container, false); ChildFragment childFragment = new ChildFragment(); getChildFragmentManager().beginTransaction().add(R.id.child_fragment_container, childFragment).commit(); return view; } public void onChildItemClick() { // Handle the item click Toast.makeText(getContext(), "Item clicked in Child Fragment!", Toast.LENGTH_SHORT).show(); } } ``` **ChildFragment.java**: ```java public class ChildFragment extends Fragment { @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View view = inflater.inflate(R.layout.fragment_child, container, false); Button button = view.findViewById(R.id.click_button); button.setOnClickListener(v -> { // Attempt to call parent's method ((ParentFragment) getParentFragment()).onChildItemClick(); }); return view; } } ``` I've tried ensuring that the parent fragment is attached before calling the method, but I still encounter the `IllegalStateException`. I also checked that the click event is triggered after the parent fragment has been completely created. What could be causing this issue? Any help would be appreciated! This is part of a larger API I'm building. What's the best practice here? I'm using Java LTS in this project. I'm open to any suggestions.