private void LoginButton_Click(object sender, RoutedEventArgs e) { if (!(DataBaseSolution.FindUser(LoginBox.Text))) { MessageBox.Show("Wskazany użytkownik nie istnieje"); } else { if ((DataBaseSolution.CheckPassword(LoginBox.Text, PasswordBox.Password)) == true) { MessageBox.Show("Podane hasło jest nieprawidłowe"); } else { User user = new User(); user.Username = LoginBox.Text; user.Password = PasswordBox.Password; MainAppWindow mainAppWindow = new MainAppWindow(user); this.Visibility = Visibility.Hidden; mainAppWindow.Show(); } } }