WPF:如何在运行时向菜单添加新的menuitem？

我有一个带菜单的简单WPF应用程序.我需要在运行时动态添加菜单项.当我只是创建一个新的菜单项,并将其添加到其父MenuItem时,无论是否调用UpdateLayout,它都不会显示在菜单中.

允许菜单在运行时动态添加其他项目必须发生什么？

注意:以下代码不起作用.

            MenuItem mi = new MenuItem();
            mi.Header = "Item to add";
            mi.Visibility = Visibility.Visible;
            //addTest is a menuitem that exists in the forms defined menu
            addTest.Items.Add(mi);
            addTest.UpdateLayout();

目前,默认菜单项在xaml文件中定义.我想在此菜单及其现有菜单项中添加其他菜单项.但是,如上所述,上述代码什么都不做.

//Add to main menu
MenuItem newMenuItem1 = new MenuItem();
newMenuItem1.Header = "Test 123";
this.MainMenu.Items.Add(newMenuItem1);

//Add to a sub item
MenuItem newMenuItem2 = new MenuItem();
MenuItem newExistMenuItem = (MenuItem)this.MainMenu.Items[0];
newMenuItem2.Header = "Test 456";
newExistMenuItem.Items.Add(newMenuItem2);

我已成功将菜单项添加到预定义的菜单项.在下面的代码中,LanguageMenu在xaml的设计视图中定义,然后在C#中添加子项.

XAML:

C#:

// Clear the existing item(s) (this will actually remove the "English" element defined in XAML)
LanguageMenu.Items.Clear(); 

// Dynamically get flag images from a specified folder to use for definingthe menu items 
string[] files = Directory.GetFiles(Settings.LanguagePath, "*.png");
foreach (string imagePath in files)
{
  // Create the new menu item
  MenuItem item = new MenuItem();

  // Set the text of the menu item to the name of the file (removing the path and extention)
  item.Header = imagePath.Replace(Settings.LanguagePath, "").Replace(".png", "").Trim("\\".ToCharArray());
  if (File.Exists(imagePath))
  {
    // Create image element to set as icon on the menu element
    Image icon = new Image();
    BitmapImage bmImage = new BitmapImage();
    bmImage.BeginInit();
    bmImage.UriSource = new Uri(imagePath, UriKind.Absolute);
    bmImage.EndInit();
    icon.Source = bmImage;
    icon.MaxWidth = 25;
    item.Icon = icon;
  }

  // Hook up the event handler (in this case the method File_Language_Click handles all these menu items)
  item.Click += new RoutedEventHandler(File_Language_Click); 

  // Add menu item as child to pre-defined menu item
  LanguageMenu.Items.Add(item); // Add menu item as child to pre-defined menu item
}

我知道这是一个老帖子,但我遇到了同样的问题.在我的情况下,问题是在XAML 中直接包含在一个.一旦我把它放在里面