如何在MVVM中将PasswordBox与wpf绑定 [英] How to bind PasswordBox with wpf in MVVM

问题描述

请告诉我如何在MVVM中将PasswordBox与wpf绑定

Please tell me how to bind the PasswordBox with wpf in MVVM

推荐答案

出于安全原因，WPF没有提供任何Dependency属性在密码框中。如果你真的想要实现你想要的，那么你可以关注 Samual Jack's [ ^ ]博客文章，他提供了一个优雅的解决方案。

For security reason WPF didn't gave any Dependency property in Password box. How ever if you really want to achieve what you want then you can follow Samual Jack's[^] blog post where he gave an elegant solution.

问题是使用PasswordBox没有Idependency属性：S

The problem is that with PasswordBox there is no Idependency property :S

使用下面的附加属性绑定密码框

Use the below attached property to bind password box

<pre>public class BoundPasswordBox
    {
        public static readonly DependencyProperty PasswordProperty = DependencyProperty.RegisterAttached("Password", typeof(string), typeof(BoundPasswordBox),
            new FrameworkPropertyMetadata(string.Empty, OnPasswordPropertyChanged));

        public static readonly DependencyProperty AttachProperty =DependencyProperty.RegisterAttached("Attach",typeof(bool), typeof(BoundPasswordBox), 
            new PropertyMetadata(false, Attach));

        private static readonly DependencyProperty IsUpdatingProperty =DependencyProperty.RegisterAttached("IsUpdating", typeof(bool),
           typeof(BoundPasswordBox));


        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);
        }

    }

添加附加属性的命名空间（here util：）并使用如下所示：

Add the namespace of attached property ("here util:") and use like below:

<passwordbox x:name="TxtPassword" util:boundpasswordbox.attach="True" util:boundpasswordbox.password="{Binding Path=Password,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged,ValidatesOnDataErrors=True,NotifyOnValidationError=True}" xmlns:util="#unknown" xmlns:x="#unknown">
</passwordbox>

这篇关于如何在MVVM中将PasswordBox与wpf绑定的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！