Loading a standard layout into a ListActivity

I'd like my App to show a warning message if there are no elements to load on a ListActivity; so I thought to write this on the onResume event:

if(elementsToLoad.size()==0) setContentView (alternative layout); else loadList();

but it crashes..开发者_StackOverflow.How could I fix this?

You can use an empty view. See setEmptyView(View emptyView) method from ListView. Or you can add view to your layout with id @android:id/empty and ListView will show it for you, if list is empty.