public MainViewModel()
 {
     //os = new OrderSystem();
     //os.StartWorkDay();
     systemController           = new SystemController();
     systemController.onProcess = new Action <string>(receiveMessage);
     this._dispatcher           = Dispatcher.CurrentDispatcher;
     systemController.RequestListOfBurgers();
     this.ListViewBurgers       = systemController.GetListViewBurger();
     this.AddToCartCommand      = new RelayCommand(param => AddToCart(), null);
     this.DeleteFromCartCommand = new RelayCommand(param => DeleteFromCart(), null);
     this.OrderBurgerCommand    = new RelayCommand(param => OrderBurger(), null);
     this.SubscribeCommand      = new RelayCommand(param => Subscribe(), null);
 }