protected override void OnStartup(StartupEventArgs e)
{
base.OnStartup(e);
BusinessLogic businessLogic = new BusinessLogic();
MainWindow mainWindow = new MainWindow();
mainWindow.Show();
Navigation = new NavigationService(mainWindow.MyFrame);
Navigation.Navigate<FirstPage>();
}
public SecondPageViewModel(INavigationService navigationService, BusinessLogic businessLogic = null)
{
this.navigationService = navigationService;
this.businessLogic = businessLogic;
}