public AdminDodajProizvod()
        {
            this.InitializeComponent();
            DataContext = new DodajProizvodViewModel();
            DataContext = new DodajPosebniProizvodViewModel();
            var currentView = SystemNavigationManager.GetForCurrentView();

            currentView.AppViewBackButtonVisibility = AppViewBackButtonVisibility.Visible;
            SystemNavigationManager.GetForCurrentView().BackRequested += ThisPage_BackRequested;
        }
        public DodavanjeProizvoda()
        {
            this.InitializeComponent();
            //MenadzerForm otvara dodavanjeProizvoda
            //stavila da se vidi back u slucaju da menadzer slucajno klikne pogresan button i sl.
            viewModel = new DodajProizvodViewModel();
            var currentView = SystemNavigationManager.GetForCurrentView();

            currentView.AppViewBackButtonVisibility = AppViewBackButtonVisibility.Visible;
            SystemNavigationManager.GetForCurrentView().BackRequested += ThisPage_BackRequested;
        }