如何将上下文菜单项添加到FlowDocumentScrollViewer中的textBox

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

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
        AddContextMenu();
    }

    private void AddContextMenu()
    {
        // 创建上下文菜单
        ContextMenu contextMenu = new ContextMenu();

        // 创建菜单项并添加到上下文菜单
        MenuItem cutMenuItem = new MenuItem();
        cutMenuItem.Header = "剪切";
        contextMenu.Items.Add(cutMenuItem);

        MenuItem copyMenuItem = new MenuItem();
        copyMenuItem.Header = "复制";
        contextMenu.Items.Add(copyMenuItem);

        MenuItem pasteMenuItem = new MenuItem();
        pasteMenuItem.Header = "粘贴";
        contextMenu.Items.Add(pasteMenuItem);

        // 将上下文菜单分配给textBox
        textBox.ContextMenu = contextMenu;

        // 启用上下文菜单
        textBox.IsEnabled = true;
    }
}