Why doesn setting IsSelected True before adding a ListBoxItem to the ListBox look right?
Again the internal ListBox state is correct, but the visual representation is wrong. In this case, the visuals fix themselves if you move the mouse over the selected item and then off it because the ListBoxItem transitions from its hover appearance to its selected appearance and the visuals update correctly. The problem here is that when IsSelected is toggled, ListBoxItem plays its state transition Storyboard immediately – but the ListBoxItem is not in the visual tree yet so Silverlight doesn’t actually apply the associated state changes. (To behave correctly in this scenario, ListBoxItem should be calling its ChangeVisualState method at the end of OnApplyTemplate and also in a handler for the Loaded event.
