如何禁用WPF TextBox中的快捷方式

         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
         xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
         mc:Ignorable="d"
         d:DesignHeight="300" d:DesignWidth="300">
   <TextBox.Resources>
       <Style TargetType="{x:Type TextBox}">
           <EventSetter Event="PreviewKeyDown" Handler="OnPreviewKeyDown"/>
        </Style>
    </TextBox.Resources>
</TextBox>

using System.Windows.Input;

public partial class MyCustomTextBox : TextBox
{
    public MyCustomTextBox()
    {
        InitializeComponent();
    }

    protected override void OnPreviewKeyDown(KeyEventArgs e)
    {
        // 禁用快捷方式
        if (Keyboard.Modifiers == ModifierKeys.Control &&
            (e.Key == Key.C || e.Key == Key.V || e.Key == Key.X))
        {
            e.Handled = true;
        }

        base.OnPreviewKeyDown(e);
    }
}