private void Application_Startup(object sender, StartupEventArgs e) { Logic.Logic logic = new Logic.Logic(); if (Settings.Default.Username.ToString() != "" && Settings.Default.Password.ToString() != "") { logic.SaveUser(Settings.Default.Username, Settings.Default.Password); } if (!logic.IsUserLogin()) { LoginPage lp = new LoginPage(); lp.Show(); } else { MainWindow window = new MainWindow(); window.Show(); } }