我花了很长时间才把它弄好。最后，我放弃了，只使用了DevExpress的PasswordBoxEdit。

这是迄今为止最简单的解决方案，因为它允许绑定而不使用任何可怕的技巧。

DevExpress网站上的解决方案

郑重声明，我和开发快递没有任何关系。

正如你所看到的，我绑定到密码，但也许它绑定到静态类..

它是一个附加属性。这种属性可以应用于任何类型的DependencyObject，而不仅仅是声明它的类型。因此，尽管它是在PasswordHelper静态类中声明的，但它还是应用于使用它的PasswordBox。

要使用这个附加属性，你只需要将它绑定到ViewModel中的Password属性:

<PasswordBox w:PasswordHelper.Attach="True" 
         w:PasswordHelper.Password="{Binding Password}"/>

对于像我这样的新手，这里有一个完整的工作样本。谢谢Konamiman。

XAML

    <PasswordBox x:Name="textBoxPassword"/>
    <Button x:Name="buttonLogin" Content="Login"
            Command="{Binding PasswordCommand}"
            CommandParameter="{Binding ElementName=textBoxPassword}"/> 

ViewModel

public class YourViewModel : ViewModelBase
{
    private ICommand _passwordCommand;
    public ICommand PasswordCommand
    {
        get {
            if (_passwordCommand == null) {
                _passwordCommand = new RelayCommand<object>(PasswordClick);
            }
            return _passwordCommand;
        }
    }

    public YourViewModel()
    {
    }

    private void PasswordClick(object p)
    {
        var password = p as PasswordBox;
        Console.WriteLine("Password is: {0}", password.Password);
    }
}

你可以用附加属性来做，看到了吗。PasswordBox with MVVM

这个实现略有不同。通过绑定ViewModel中的属性将PasswordBox传递给View。它不使用任何命令参数。ViewModel对视图保持无知。 我有一个VB VS 2010项目，可以从SkyDrive下载。WPF MVVM PassWordBox Example.zip

我在WPF MVVM应用程序中使用PasswordBox的方式非常简单，对我来说工作得很好。

基本上你创建了一个公共只读属性，视图可以绑定到PasswordBox(实际控件):

Private _thePassWordBox As PasswordBox
Public ReadOnly Property ThePassWordBox As PasswordBox
    Get
        If IsNothing(_thePassWordBox) Then _thePassWordBox = New PasswordBox
        Return _thePassWordBox
    End Get
End Property

我使用了一个支持字段来完成属性的自我初始化。

然后从Xaml中绑定ContentControl或Control Container的内容:

 <ContentControl Grid.Column="1" Grid.Row="1" Height="23" Width="120" Content="{Binding Path=ThePassWordBox}" HorizontalAlignment="Center" VerticalAlignment="Center" />

从那里你可以完全控制密码盒。我还使用PasswordAccessor(只是一个字符串的函数)返回密码值时，做登录或任何其他你想要的密码。在这个例子中，我在通用用户对象模型中有一个公共属性。 例子:

Public Property PasswordAccessor() As Func(Of String)

在用户对象中，密码字符串属性是只读的，没有任何备份存储。它只是从PasswordBox返回Password。 例子:

Public ReadOnly Property PassWord As String
    Get
        Return If((PasswordAccessor Is Nothing), String.Empty, PasswordAccessor.Invoke())
    End Get
End Property

然后在ViewModel中，我确保Accessor被创建并设置为PasswordBox。密码属性:

Public Sub New()
    'Sets the Accessor for the Password Property
    SetPasswordAccessor(Function() ThePassWordBox.Password)
End Sub

Friend Sub SetPasswordAccessor(ByVal accessor As Func(Of String))
    If Not IsNothing(VMUser) Then VMUser.PasswordAccessor = accessor
End Sub

当我需要密码字符串说登录，我只是得到用户对象密码属性，真正调用函数抓取密码并返回它，然后实际的密码不存储在用户对象。 例如:将在ViewModel中

Private Function LogIn() as Boolean
    'Make call to your Authentication methods and or functions. I usally place that code in the Model
    Return AuthenticationManager.Login(New UserIdentity(User.UserName, User.Password)
End Function

That should do it. The ViewModel doesn't need any knowledge of the View's Controls. The View just binds to the Property in the ViewModel, not any different than the View Binding to an image or other resource. In this case that resource(Property) just happens to be a usercontrol. It allows for testing as the ViewModel creates and owns the Property and the Property is independent of the View. As for security I don't know how good this implementation is. But by using a Function the value is not stored in the Property itself just accessed by the Property.

为了在不破坏MVVM的情况下解决OP问题，我将使用自定义值转换器和必须从密码框中检索的值(密码)的包装器。

public interface IWrappedParameter<T>
{
    T Value { get; }
}

public class PasswordBoxWrapper : IWrappedParameter<string>
{
    private readonly PasswordBox _source;

    public string Value
    {
        get { return _source != null ? _source.Password : string.Empty; }
    }

    public PasswordBoxWrapper(PasswordBox source)
    {
        _source = source;
    }
}

public class PasswordBoxConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        // Implement type and value check here...
        return new PasswordBoxWrapper((PasswordBox)value);
    }

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        throw new InvalidOperationException("No conversion.");
    }
}

在视图模型中:

public string Username { get; set; }

public ICommand LoginCommand
{
    get
    {
        return new RelayCommand<IWrappedParameter<string>>(password => { Login(Username, password); });
    }
}

private void Login(string username, string password)
{
    // Perform login here...
}

因为视图模型使用IWrappedParameter<T>，所以它不需要任何关于PasswordBoxWrapper或PasswordBoxConverter的知识。这样您就可以将PasswordBox对象与视图模型隔离开来，并且不会破坏MVVM模式。

在视图中:

<Window.Resources>
    <h:PasswordBoxConverter x:Key="PwdConverter" />
</Window.Resources>
...
<PasswordBox Name="PwdBox" />
<Button Content="Login" Command="{Binding LoginCommand}"
        CommandParameter="{Binding ElementName=PwdBox, Converter={StaticResource PwdConverter}}" />