WPF 先显示登录成功，验证成功后显示主窗口

/// 设置显示登录窗口的方法：
/// 在 App.xaml 中把这句
/// 删掉 StartupUri="MainWindow.xaml" 改为 StartupUri="Login/LoginWindow.xaml" // Login/LoginWindow.xaml是登录窗口;
/// 加上 ShutdownMode="OnLastWindowClose"

代码如下：

    public partial class LoginWindow : Window
    {
        public LoginWindow()
        {
            InitializeComponent();
        }

        private void btnClose_Click(object sender, RoutedEventArgs e)
        {
            System.Windows.Application.Current.Shutdown();
        }

        private void btnLogin_Click(object sender, RoutedEventArgs e)
        {
            if (user_name.Text != LoginConfig.GetSettingString("UserName") || 
                password.Password != LoginConfig.GetSettingString("Password"))
            {
                MessageBox.Show("用户名或密码错误！");
            }
            else
            {
                (new MainWindow()).Show(); // 显示主窗口;
                Close();
            }
        }
    }