//Переопределяем метод OnStartup protected override async void OnStartup(StartupEventArgs e) { base.OnStartup(e); MainWindowViewModel = new MainViewModel(); Internet = new InternetConnection(); IsHaveInternetConnection = Internet.CheckInternetConnection(); if (!IsHaveInternetConnection) { MainWindowViewModel.StatusValue = "Check your internet connection"; } await displayRootRegistry.ShowModalPresendation(MainWindowViewModel); }