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WPF 为PasswordBox控件的Password增加绑定功能

在WPF中,PasswordBox 控件本身 Password 属性是不支持直接绑定的,在使用绑定的时候略显得麻烦。所以我们做一个附加属性上去,然后进行绑定并且控制PasswordBox控件的Password属性的值与我们自己定义的附加属性同步,这样就完美了。

 

下面是编写的Password附加属性帮助类的代码

    /// <summary>  
    /// 为PasswordBox控件的Password增加绑定功能  
    /// </summary>  
    public static 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);
        }
    }

 

调用方式

<PasswordBox Width="300" Margin="5" c:PasswordBoxHelper.Password="{Binding Path=LoginUser.Password,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}"></PasswordBox>

这里 c 为该帮助类的xmlns命名空间。

LoginUser.Password 为绑定的对象

转载请注明出处王旭博客 » WPF 为PasswordBox控件的Password增加绑定功能

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评论 2

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  1. #2

    天书 对于不懂的人来说 就是一个个符号字母吧!!

    多片锯2年前 (2014-10-17)回复
  2. #1

    :mrgreen: 对我来说,这些东西就是天书,

    凌吉林博客2年前 (2014-10-15)回复