密碼輸入框需要輸入的密碼不能顯示明文，用其他的特殊字元代替顯示。
顯示效果如下：

Xaml部分程式碼如下：

<Window x:Class="TextBoxPwd.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
 

        xmlns:local="clr-namespace:TextBoxPwd"
        mc:Ignorable="d"
        Title="MainWindow" Height="350" Width="525">
    <StackPanel>
        <TextBox FontFamily="Courier New" x:Name="pwd" FontSize="20" Foreground="Transparent" Text="sdfsddfsfs"/>

        <TextBox FontFamily
 
="Courier New"  FontSize="20"  Text="sdfsddfsfs"/>

    </StackPanel>
</Window>

後臺程式碼如下：

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 TextBoxPwd
{
    /// <summary>
    /// MainWindow.xaml 的互動邏輯
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
            pwd.TextDecorations = new TextDecorationCollection(new TextDecoration[] {
                new TextDecoration() {
                     Location= TextDecorationLocation.Strikethrough,
                      Pen= new Pen(Brushes.Black, 10f) {
                          DashCap =  PenLineCap.Round,
                           StartLineCap= PenLineCap.Round,
                            EndLineCap= PenLineCap.Round,
                             DashStyle= new DashStyle(new double[] {0.0,1.2 }, 0.6f)
                      }
                }

            });

        }
    }
}