public NavigationService(NavigationDataBag navigationDataBag, INavigationRouteService navigationRouteService, MvvmApp mvvmApp)
        {
            this.navigationDataBag      = navigationDataBag;
            this.navigationRouteService = navigationRouteService;
            this.mvvmApp = mvvmApp;
            this.mvvmApp.FormsApplication.PropertyChanged += FormsApplication_PropertyChanged;

            if (this.mvvmApp.FormsApplication.MainPage != null)
            {
                this.OnMainPageChanged();
            }
        }
 public MvvmEngine(IServiceScopeFactory serviceScopeFactory, NavigationDataBag navigationDataBag)
 {
     this.serviceScopeFactory = serviceScopeFactory;
     this.navigationDataBag   = navigationDataBag;
 }