Question

我在WPF中使用密码框，当我处于编辑模式时，密码框不会掩盖我的密码。

以下是我的代码示例。

<PasswordBox Width="200" Password="{Binding Path=Password, ValidatesOnDataErrors=True, NotifyOnValidationError=True, Mode=TwoWay}"  HorizontalAlignment="Left"/>

我尝试过包括Passwordchar =＆＃39; *＆＃39;

Answer 1

由于安全目的，您无法在viewmodel中直接获取密码值，因此您必须创建依赖属性。

下面是密码的代码。

DP：

public static readonly DependencyProperty BoundPassword =
        DependencyProperty.RegisterAttached("BoundPassword", typeof(string), typeof(PasswordBoxHelper), new PropertyMetadata(string.Empty, OnBoundPasswordChanged));

    public static readonly DependencyProperty BindPassword = DependencyProperty.RegisterAttached(
        "BindPassword", typeof(bool), typeof(PasswordBoxHelper), new PropertyMetadata(false, OnBindPasswordChanged));

    private static readonly DependencyProperty UpdatingPassword =
        DependencyProperty.RegisterAttached("UpdatingPassword", typeof(bool), typeof(PasswordBoxHelper), new PropertyMetadata(false));

    private static void OnBoundPasswordChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        var box = d as PasswordBox;
        if(d == null || !GetBindPassword(d))
        {
            return;
        }
        box.PasswordChanged -= HandlePasswordChanged;

        var newPassword = (string)e.NewValue;

        if(!GetUpdatingPassword(box))
        {
            box.Password = newPassword;
        }

        box.PasswordChanged += HandlePasswordChanged;
    }

    private static void OnBindPasswordChanged(DependencyObject dp, DependencyPropertyChangedEventArgs e)
    {

        var box = dp as PasswordBox;

        if(box == null)
        {
            return;
        }

        bool wasBound = (bool)(e.OldValue);
        bool needToBind = (bool)(e.NewValue);

        if(wasBound)
        {
            box.PasswordChanged -= HandlePasswordChanged;
        }

        if(needToBind)
        {
            box.PasswordChanged += HandlePasswordChanged;
        }
    }

    private static void HandlePasswordChanged(object sender, RoutedEventArgs e)
    {
        var box = sender as PasswordBox;
        SetUpdatingPassword(box, true);
        SetBoundPassword(box, box.Password);
        SetUpdatingPassword(box, false);
    }

    public static void SetBindPassword(DependencyObject dp, bool value)
    {
        dp.SetValue(BindPassword, value);
    }

    public static bool GetBindPassword(DependencyObject dp)
    {
        return (bool)dp.GetValue(BindPassword);
    }

    public static string GetBoundPassword(DependencyObject dp)
    {
        return (string)dp.GetValue(BoundPassword);
    }

    public static void SetBoundPassword(DependencyObject dp, string value)
    {
        dp.SetValue(BoundPassword, value);
    }

    private static bool GetUpdatingPassword(DependencyObject dp)
    {
        return (bool)dp.GetValue(UpdatingPassword);
    }

    private static void SetUpdatingPassword(DependencyObject dp, bool value)
    {
        dp.SetValue(UpdatingPassword, value);
    }

以下是XAML：

  <PasswordBox x:Name="PasswordBox" 
                                     utility:PasswordBoxHelper.BindPassword="true" 
                                     utility:PasswordBoxHelper.BoundPassword="{Binding Path=Password,  
        Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"/>

Answer 2

由于安全性，您无法在PasswordBox中使用Binding to password字段。实际上你可以，但你的密码将存储在内存中。试试这个http://blog.functionalfun.net/2008/06/wpf-passwordbox-and-data-binding.html

Answer 3

@JRB和@BorisErmako答案都可能有效，但不知何故重量级。

您不需要双向数据绑定，对吗？在大多数情况下，您不想从代码中更新密码字段，对吗？我想你不会。

然后，只需使用一个事件来获得通知。灵感来自Bind a WPF passwordbox我做了：

XAML：

<PasswordBox PasswordChanged="OnPasswordChanged" />

代码隐藏事件处理程序：

假设代码隐藏类具有指向底层模型对象的指针myViewModelObject。

private void OnPasswordChanged(object sender, RoutedEventArgs e)
{
    myViewModelObject.Password = ((PasswordBox)sender).Password;
}

与其他答案的89到108个额外行相比，这增加了很少的代码行。额外奖励：出于所有实际目的，这似乎与ReactiveUI等高级框架完全兼容。

Answer 4

要在WPF中使用带掩码的密码文本框，请实施以下方法：

类构造函数：

 public Login_Form()
        {
            InitializeComponent();
            Password_Text_Box.MaxLength = 7; // password 7 characters in length
            AutoValidate = AutoValidate.Disable;
        } // End of Login form initialization

组件验证：

  private void Password_Text_Box_Validating(object sender, System.ComponentModel.CancelEventArgs e) {
            bool cancel = false;
            if (string.IsNullOrEmpty(Password_Text_Box.Text)) {
                cancel = true;
                ErrorProvider.SetError(Password_Text_Box, " MISSING PASSWORD "); }
            e.Cancel = cancel; }

“按键”操作背后的逻辑：

private void Password_Text_Box_KeyPress(object sender, KeyPressEventArgs e) {
        if (e.KeyChar == (char)Keys.Enter) {
            // if ENTER is hit , do something
            e.Handled = true; //Handle the Keypress event (suppress the Beep) }
        Password_Text_Box.PasswordChar = '*'; // masking input right away
        e.Handled = !(char.IsDigit(e.KeyChar) || e.KeyChar == (char)Keys.Back);
        e = null;} // not allowing certain types of input

您还可以实施象形图来显示和隐藏输入的序列：

   private void pictureBoxShowPassword_Click(object sender, EventArgs e) {
       if (Password_Text_Box.PasswordChar == '*' & Password_Text_Box.Text != null) {
                Password_Text_Box.PasswordChar = '\0'; } //revealing
            else if (Password_Text_Box.PasswordChar == '\0'){
                Password_Text_Box.PasswordChar = '*'; } } // hiding

当您指向并单击文本框时会发生什么：

    private void Password_Text_Box_MouseDown(object sender, MouseEventArgs e) {
        if (Password_Text_Box.Text == "Password") {
            Password_Text_Box.Text = ""; } }

总而言之，您应该遵循以下思路：

加载表单和文本框时，它将显示文本-组件的用途。当用户指向鼠标并单击组件时，目的文本消失。输入值后，屏幕上会出现一个遮罩符号。通过“显示”按钮附近的，您可以在提交之前看到输入的值。

密码框不会掩盖我的密码WPF

4 个答案:

XAML：

代码隐藏事件处理程序：