android-fragments-events.md

title: Android: Fragments: Communicating events date: 2012-03-24 13:30:13 tags: android,android-fragments

In your Fragment class, if you create listener on a particular interface, and make the parent implement that interface, you can communicate via events.

First create the interface:

	public interface OnNewFragmentPressed {
		void onNewFragmentPressed();
	}

Then create a listener method of that interface.

	public static class NewFragment extends Fragment {
	    private OnNewFragmentPressed mListener;
	}

Then in the onAttach() method of your Fragment, use the passed in Activity to make sure it implements the interface, and set the listener to that.

	@Override
	public void onAttach(Activity activity) {
		super.onAttach(activity);
		try {
		   mListener = (OnNewFragmentPressed) activity;
		} catch(ClassCastException e) {
		   throw new ClassCastException(activity.toString() + ” didn’t implement OnNewFragmentPressed”);
		}
	}   

Now you can call methods of that interface, thereby interacting with your parent Activity.