protected override async void OnStartup(StartupEventArgs e) { // Register with notification platform await DesktopNotificationManagerCompat.RegisterWithPlatformAsync <MyNotificationActivator>( aumid : "Microsoft.WpfDesktopToasts7", displayName : "WPF Desktop Toasts 7", logo : "C:\\logo.png", logoBackgroundColor : "transparent"); // And then register COM server and activator type DesktopNotificationManagerCompat.RegisterComServerAndActivator <MyNotificationActivator>(); // If launched from a toast if (e.Args.Contains("-ToastActivated")) { // Our NotificationActivator will handle showing windows if necessary base.OnStartup(e); return; } // Show the window new MainWindow().Show(); base.OnStartup(e); }