private static void Main() { var windowMediator = new WindowMediator(); var optionsWindow = new OptionsWindow(windowMediator); var userManagerWindow = new UserManagerWindow(windowMediator); var mainWindow = new MainWindow(windowMediator); optionsWindow.Notify("Notifying only options window!"); windowMediator.Register(mainWindow); windowMediator.Register(optionsWindow); windowMediator.Register(userManagerWindow); windowMediator.Broadcast("This is a broadcasted message to all windows"); Console.ReadKey(); }