ComboBoxMenu_SelectionChanged - standard implementation?

Question

WPF

on msdn, this is the standard implementation for the SelectionChanged handler:

ListBoxItem lbi = ((sender as ListBox).SelectedItem as ListBoxItem);

- I get a NullReferenceException. Why?

Answer 1

You will be defined at you ListBox or ComboBox.
In the header of the ComboBox, so when the event is fired, you have a sender of type ComboBox, not the ListBox you are casting to.