使用 Catel 将视图属性映射到 ViewModel

Question

我正在进行登录视图。问题是 PasswordBox 无法绑定到视图模型，因此我将视图的属性映射到视图模型。

这是视图

public partial class LoginView : MetroDataWindow
{
    /// <summary>
    /// Initializes a new instance of the <see cref="LoginView"/> class.
    /// </summary>
    public LoginView()
        : this(null) { }

    /// <summary>
    /// Initializes a new instance of the <see cref="LoginView"/> class.
    /// </summary>
    /// <param name="viewModel">The view model to inject.</param>
    /// <remarks>
    /// This constructor can be used to use view-model injection.
    /// </remarks>
    public LoginView(LoginViewModel viewModel)
        : base(viewModel)
    {
        InitializeComponent();
    }

    [ViewToViewModel(MappingType = ViewToViewModelMappingType.ViewToViewModel)]
    public SecureString Contrasena
    {
        get { return (SecureString)GetValue(ContrasenaPropiedad); }
        set { SetValue(ContrasenaPropiedad, value); }
    }

    // Using a DependencyProperty as the backing store for MapCenter.  This enables animation, styling, binding, etc...
    public static readonly DependencyProperty ContrasenaPropiedad = DependencyProperty.Register("Contrasena", typeof(SecureString),
        typeof(LoginView), new PropertyMetadata(null, (sender, e) => ((LoginView)sender).UpdateContrasena()));

    private void UpdateContrasena()
    {
        MessageBox.Show("VIEW: FirstName changed to " + ContrasenaPropiedad.ToString());
    }

    private void tbPassword_PasswordChanged(object sender, RoutedEventArgs e)
    {
        Contrasena = tbPassword.SecurePassword;

    }

    protected override void OnPropertyChanged(DependencyPropertyChangedEventArgs e)
    {
        base.OnPropertyChanged(e);

        if (e.Property == ContrasenaPropiedad)
        {
            int i = 0;
        }
    }
}

这是带有属性

的视图模型部分

public static readonly PropertyData ContrasenaPropiedad = RegisterProperty("Contrasena", typeof(SecureString), null, (sender, e) => ((LoginViewModel)sender).OnContrasenaChange());

    public void OnContrasenaChange()
    {
        _messageService.Show("VIEW MODEL: FirstName changed to " + Contrasena.ToString());
    }

    public SecureString  Contrasena
    {
        get
        {
            return GetValue<SecureString >(ContrasenaPropiedad);
        }
        set
        {
            SetValue(ContrasenaPropiedad, value);
        }
    }

viewmodel 的 onChange 函数永远不会触发。

我将此代码基于此问题最后一条评论中给出的示例

Catel ViewToViewModel attribute

但是没有用。我是不是遗漏了什么，或者那里评论的错误从未修复过？

此外，由于视图是唯一更改属性的视图，我应该改用 ViewToViewModelMappingType.ViewToViewModel 类型吗？它会以任何方式改变映射的实现吗？

Answer 1

密码是一种特殊的品种。但是 Catel 有解决这个问题的方法，UpdateBindingOnPasswordChanged 行为：

<PasswordBox>
   <i:Interaction.Behaviors>
         <catel:UpdateBindingOnPasswordChanged Password="{Binding Password, Mode=TwoWay}" />
   </i:Interaction.Behaviors>
</PasswordBox>

ps。你知道 Catel.Fody 吗？它使您的代码更易读，更易于编写。

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