In the app, there are two views, one is Listbox. The two views are switched by using Tabgroup. By implement the draw() method of Listbox, it can show the background color. But if want to dynamically change the background color triggered by the other view, it doesn't work. Try to call drawnow() in view's Doactivate(), still the background color won't change.

Anyone knows what is the problem and any hint to make it work?