Called by the framework to show popup menu associated with the ToolbarMenuButton at the specified point.
Overriden from the ToolbarMenuButton. Called by the framework to display popup menu associated with the ToolbarBaseControlButton. In ToolbarBaseControlButton class returns a null reference.
Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2