wpf中PassWord绑定

页面：

<Window
xmlns:local="clr-namespace:项目名称.Common"
/>

<PasswordBox local:PasswordBoxHelper.Attach="True"
             local:PasswordBoxHelper.Password="{Binding Path=LoginData.Password, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"
             Background="Transparent"
             VerticalContentAlignment="Center"
             CaretBrush="White" Cursor="IBeam"/>

 

后台 ：

项目名称.Common中添加 PasswordBoxHelper.cs

 public  class PasswordBoxHelper
    {
        public static readonly DependencyProperty PasswordProperty = DependencyProperty.RegisterAttached("Password", typeof(string), typeof(PasswordBoxHelper), new FrameworkPropertyMetadata(string.Empty, OnPasswordPropertyChanged));
        public static readonly DependencyProperty AttachProperty = DependencyProperty.RegisterAttached("Attach",typeof(bool), typeof(PasswordBoxHelper), new PropertyMetadata(false, Attach));
        private static readonly DependencyProperty IsUpdatingProperty = DependencyProperty.RegisterAttached("IsUpdating", typeof(bool), typeof(PasswordBoxHelper));


        public static void SetAttach(DependencyObject dp, bool value)
        {
            dp.SetValue(AttachProperty, value);
        }
        public static bool GetAttach(DependencyObject dp)
        {
            return (bool)dp.GetValue(AttachProperty);
        }
        public static string GetPassword(DependencyObject dp)
        {
            return (string)dp.GetValue(PasswordProperty);
        }
        public static void SetPassword(DependencyObject dp, string value)
        {
            dp.SetValue(PasswordProperty, value);
        }
        private static bool GetIsUpdating(DependencyObject dp)
        {
            return (bool)dp.GetValue(IsUpdatingProperty);
        }
        private static void SetIsUpdating(DependencyObject dp, bool value)
        {
            dp.SetValue(IsUpdatingProperty, value);
        }
        private static void OnPasswordPropertyChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e)
        {
            PasswordBox passwordBox = sender as PasswordBox;
            passwordBox.PasswordChanged -= PasswordChanged;
            if (!(bool)GetIsUpdating(passwordBox))
            {
                passwordBox.Password = (string)e.NewValue;
            }
            passwordBox.PasswordChanged += PasswordChanged;
        }
        private static void Attach(DependencyObject sender, DependencyPropertyChangedEventArgs e)
        {
            PasswordBox passwordBox = sender as PasswordBox;
            if (passwordBox == null)
                return;
            if ((bool)e.OldValue)
            {
                passwordBox.PasswordChanged -= PasswordChanged;
            }
            if ((bool)e.NewValue)
            {
                passwordBox.PasswordChanged += PasswordChanged;
            }
        }
        private static void PasswordChanged(object sender, RoutedEventArgs e)
        {
            PasswordBox passwordBox = sender as PasswordBox;
            SetIsUpdating(passwordBox, true);
            SetPassword(passwordBox, passwordBox.Password);
            SetIsUpdating(passwordBox, false);
        }