PasswordBox

Password实现绑定

xmlns:utl="clr-namespace:Project1.Utility"
utl:PasswordBoxHelper.Password="{Binding ConfirmPassword, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"/>

using System.Windows;
using System.Windows.Controls;

public class PasswordBoxHelper
{
    // 防止附加属性值与控件属性值循环触发复制
    private static bool _bUpdating = false;

    public static string GetPassword(DependencyObject obj)
    {
        return (string)obj.GetValue(PasswordProperty);
    }
    public static void SetPassword(DependencyObject obj, string value)
    {
        obj.SetValue(PasswordProperty, value);
    }
    public static readonly DependencyProperty PasswordProperty =
        DependencyProperty.RegisterAttached("Password", typeof(string), typeof(PasswordBoxHelper), new PropertyMetadata(null, OnPasswordPropertyChanged));


    public static bool GetAttach(DependencyObject obj)
    {
        return (bool)obj.GetValue(AttachProperty);
    }
    public static void SetAttach(DependencyObject obj, bool value)
    {
        obj.SetValue(AttachProperty, value);
    }
    public static readonly DependencyProperty AttachProperty =
        DependencyProperty.RegisterAttached("Attach", typeof(bool), typeof(PasswordBoxHelper), new PropertyMetadata(false, OnAttachPropertyChanged));

    /// <summary>
    /// 附加属性值变化后推给 控件
    /// </summary>
    /// <param name="d"></param>
    /// <param name="e"></param>
    private static void OnPasswordPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        if (d is PasswordBox pbox)
        {
            pbox.PasswordChanged -= Password_PasswwordChanged;
            if (_bUpdating)
            {
                pbox.Password = e.NewValue?.ToString();
                int start = (pbox.Password ?? string.Empty).Length;
                SetCursor(pbox, start);
            }
            pbox.PasswordChanged += Password_PasswwordChanged;
        }
    }

    /// <summary>
    /// 控件的值变化后推送给 附加属性
    /// </summary>
    /// <param name="d"></param>
    /// <param name="e"></param>
    private static void OnAttachPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        if (d is PasswordBox pbox)
        {
            pbox.PasswordChanged -= Password_PasswwordChanged;
            pbox.PasswordChanged += Password_PasswwordChanged;
            _bUpdating = (bool)e.NewValue;
        }
    }

    private static void Password_PasswwordChanged(object sender, RoutedEventArgs e)
    {
        if (sender is PasswordBox pbox)
        {
            _bUpdating = true;
            SetPassword(pbox, pbox.Password);
            _bUpdating = false;
        }
    }
}

设置光标位置

/// <summary>
/// 设置光标位置
/// </summary>
/// <param name="pbox"></param>
/// <param name="index"></param>
private static void SetCursor(PasswordBox pbox, int index)
{
    if (index < 0)
    {
        return;
    }
    if (index > pbox.Password.Length)
    {
        index = pbox.Password.Length;
    }
    pbox.GetType().GetMethod("Select", System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.NonPublic)
                .Invoke(pbox, new object[] { index, 0 });
}