Fires on the server side before the expansion state of a group is changed.
The ExpandedChanging event's data class is NavBarGroupCancelEventArgs. The following properties provide information specific to this event:
|Cancel||Gets or sets a value indicating whether the command which raised an event should be canceled.|
|Group||Gets a group for which the event is fired. Inherited from NavBarGroupEventArgs.|
Write an ExpandedChanging event handler to perform specific actions on the server side each time before a group’s expansion state is changed. You can use the event parameter’s properties to identify the group being manipulated and cancel execution of the command, if necessary.