6. June 2011 13:01
Faced an interesting problem: when I want to change ApplicationBar visibility by by changing instance IsVisible property, I always get NullReference exception. To avoid this use static member instead:
ApplicationBar.IsVisible = true;
Guess why? Because ApplicationBar is not a Silverlight element and general behavior doesn’t apply to it.
Update: the same happens when you want to add/remove a button – so use static Button property.