由于PasswordBox.Password属性非依赖属性，所以不能作为绑定的目标，以下是本人的MVVM实现方法。
PasswordBox.Password与TextBox.Text同步，TextBox只是为了演示，实际使用的是TextBox.Text绑定的Source。
通过Behavior添加PasswordChanged事件的事件处理器，以及自定义一个附加属性实现绑定，Behavior需要引用System.Windows.Interactivity.dll，代码如下：
using System.Windows; using System.Windows.Controls; using System.Windows.Interactivity; namespace PasswordHelperTest
{ public static class PasswordBoxHelper
{ public static readonly DependencyProperty PasswordProperty = DependencyProperty.RegisterAttached(“Password”, typeof(string), typeof(PasswordBoxHelper), new FrameworkPropertyMetadata(string.Empty, OnPasswordPropertyChanged)); private static void OnPasswordPropertyChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e)
{
PasswordBox passwordBox = sender as PasswordBox; string password = (string)e.NewValue; if (passwordBox != null && passwordBox.Password != password)
{
passwordBox.Password = password;
}
} public static string GetPassword(DependencyObject dp)
{ return (string)dp.GetValue(PasswordProperty);
} public static void SetPassword(DependencyObject dp, string value)
{
dp.SetValue(PasswordProperty, value);
}
} public class PasswordBoxBehavior : Behavior
{ base.OnAttached();
AssociatedObject.PasswordChanged += OnPasswordChanged;
} private static void OnPasswordChanged(object sender, RoutedEventArgs e)
{
PasswordBox passwordBox \= sender as PasswordBox; string password = PasswordBoxHelper.GetPassword(passwordBox); if (passwordBox != null && passwordBox.Password != password)
{
PasswordBoxHelper.SetPassword(passwordBox, passwordBox.Password);
}
} protected override void OnDetaching()
{ base.OnDetaching();
AssociatedObject.PasswordChanged \-= OnPasswordChanged;
}
}
}
View代码如下：
<Window x:Class=”PasswordHelperTest.MainWindow” xmlns=“http://schemas.microsoft.com/winfx/2006/xaml/presentation“ xmlns:x=“http://schemas.microsoft.com/winfx/2006/xaml“ xmlns:i=“http://schemas.microsoft.com/expression/2010/interactivity“ xmlns:local=“clr-namespace:PasswordHelperTest” Title=“MainWindow” Height=”350” Width=”525”>
<PasswordBox Margin=”3” local:PasswordBoxHelper.Password=”{Binding Path=Password,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}”>
<i:Interaction.Behaviors>
<local:PasswordBoxBehavior />
</i:Interaction.Behaviors>
<TextBox Margin=”3” Text=”{Binding Path=Password,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}”>
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Windows; using System.Windows.Controls; using System.Windows.Data; using System.Windows.Documents; using System.Windows.Input; using System.Windows.Media; using System.Windows.Media.Imaging; using System.Windows.Navigation; using System.Windows.Shapes; namespace PasswordHelperTest
{ ///
/// MainWindow.xaml 的交互逻辑 ///
public partial class MainWindow : Window
{ public MainWindow()
{
InitializeComponent(); this.DataContext = new MainWindowViewModel();
}
}
}
ViewModel引用Microsoft.Practices.Prism.dll，代码如下：
using Microsoft.Practices.Prism.ViewModel; using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace PasswordHelperTest
{ class MainWindowViewModel : NotificationObject
{ private string _password; public string Password
{ get { return _password; } set { if (_password != value)
{
_password = value; this.RaisePropertyChanged(“Password”);
}
}
}
}
}
