public MainWindow() { Startup.ClientServices = services => { services.Replace(new ServiceDescriptor(typeof(IFileSystem), typeof(FileSystem), ServiceLifetime.Singleton)); services.Replace(new ServiceDescriptor(typeof(IDesktopWindow), this)); }; InitializeComponent(); CustomToolbar.MouseDown += TopMenuBar_MouseDown; Uri imagePath = new Uri("Logo_Watermark.png", UriKind.Relative); BackgroundImage.ImageSource = new BitmapImage(imagePath); Provider = Startup.GetProvider(); DesktopService = Provider.GetService <IDesktopService>(); AppSettings = Provider.GetService <IAppSettings>(); FileSystem = Provider.GetService <IFileSystem>(); SubscribeToServiceEvents(); Startup.DesktopServicesAreReady(); DesktopService.RunStartup(); }