A method that will handle specific command events concerning manipulations with group headers.
public delegate void GroupHeaderCommandEventHandler( object source, GroupHeaderCommandEventArgs e );
Public Delegate Sub GroupHeaderCommandEventHandler( source As Object, e As GroupHeaderCommandEventArgs )
A GroupHeaderCommandEventArgs object that contains event data.
When creating a GroupHeaderCommandEventHandler delegate, you identify the method that will handle the corresponding event. To associate an event with your event handler, add a delegate instance to the event. The event handler is called whenever the event occurs unless you remove the delegate. For more information about event handler delegates, see Events and Delegates in MSDN.