Represents a method that will handle the NavBarControl.ActiveGroupChanged event.
An object representing the source of the event (typically the NavBarControl).
A NavBarGroupEventArgs object that contains event data.
When you create a NavBarGroupEventHandler delegate, you identify the method that will handle the event. To associate the event with your event handler, add an instance of the delegate to the event. The event handler is called whenever the event occurs, unless you remove the delegate.