private static void RegisterListener()
        {
            var service = VirtualDesktopInteropHelper.GetVirtualDesktopNotificationService();

            listener = new VirtualDesktopNotificationListener();
            dwCookie = service.Register(listener);
        }
        private static void UnregisterListener()
        {
            if (dwCookie == null)
            {
                return;
            }

            var service = VirtualDesktopInteropHelper.GetVirtualDesktopNotificationService();

            service.Unregister(dwCookie.Value);
        }