Returns the navbar's active group.
A ASPxClientNavBarGroup object that represents the active group.
When the ASPxNavBar.AutoCollapse property of a navbar control is set to true, only one group can be expanded within the navbar at a time. This single expanded group is called the navbar's active group. In this mode, the GetActiveGroup method can be used on the client side to obtain the active group within the navbar control.
Note that if the ASPxNavBar.AutoCollapse property is set to false, the GetActiveGroup method is not in effect and returns null (Nothing in Visual Basic).