Changed Event Handler
Represents the method that will handle the UserPreferenceChanged event.
public delegate void UserPreferenceChangedEventHandler(object sender, UserPreferenceChangedEventArgs e);
The source of the event. When this event is raised by the SystemEvents class, this object is always
A UserPreferenceChangedEventArgs that contains the event data.
When you create a UserPreferenceChangedEventHandler delegate, you identify the method that will handle the event. To associate the event with your event-handling method, add an instance of the delegate to the event. The event-handling method is called whenever the event occurs, unless you remove the delegate. For more information about event-handler delegates, see NIB: Events and Delegates.