Nullpointerexception thrown when trying to findViewById

Question

I have the following Activity:

public class MainActivity extends ActionBarActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    supe         


        

Answer 1

Try to implement your onCreateView(...) in Fragment like

@Override
 public View onCreateView(LayoutInflater inflater, ViewGroup container,
 Bundle savedInstanceState) {
 View rootView = inflater.inflate(R.layout.fragment_main, container,
  false);

 View something = rootView.findViewById(R.id.something);
 something.setOnClickListener(new View.OnClickListener() { ... });

return rootView;
}

The Button is in the fragment layout (fragment_main.xml) and not in the activity layout (activity_main.xml). onCreate() is too early in the lifecycle to find it in the activity view hierarchy, and a null is returned. Invoking a method on null causes the NPE.