Assembly: PresentationFramework (in PresentationFramework.dll)
The event data that the parameter e provides contains an DependencyPropertyChangedEventArgs::OldValue and a PropertyDataChangedEventArgs::NewValue. The DependencyPropertyChangedEventArgs::OldValue is set to the item that was previously selected, or is set to nullptr if there is no previously selected item. Similarly, the PropertyDataChangedEventArgs::NewValue is set to the newly selected item, or is set to nullptr if no new item is selected.
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2