www

            <Menu  x:Name="menuTop"
                   ItemsSource="{Binding  Path=QueryEditorMenu}">
                <Menu.ItemContainerStyle>
                    <Style  TargetType="MenuItem">
                        <Setter Property="Header"
                                Value="{Binding Title}"></Setter>
                        <Setter Property="Command"
                                Value="{Binding Command}"></Setter>
                        <Setter Property="CommandParameter"
                                Value="{Binding NameSpace}"></Setter>
                        <Setter Property="Tag"
                                Value="{Binding Tag}"></Setter>
                        <Setter Property="ItemsSource"
                                Value="{Binding SubItems}"></Setter>

                        <Setter Property="InputGestureText"
                                Value="{Binding ShortcutKey}" />
                    </Style>
                </Menu.ItemContainerStyle>
            </Menu>

　　

    public class MenuBar:BindableBase
    {

        private string _icon;
        public string Icon
        {
            get { return _icon; }
            set
            {
                SetProperty(ref _icon, value);
            }
        }
        private string _tag;

        public string Tag
        {
            get { return _tag; }
            set
            {
                SetProperty(ref _tag, value);
            }
        }



        private string title;
        /// <summary>
        /// 菜单标题
        /// </summary>
        public string Title
        {
            get { return title; }
            set { title = value; }
        }


        private string shortcutKey;
        /// <summary>
        /// 菜单快捷键
        /// </summary>
        public string ShortcutKey
        {
            get { return shortcutKey; }
            set { shortcutKey = value; }
        }


        private string nameSpace;
        /// <summary>
        /// 命名空间
        /// </summary>
        public string NameSpace
        {
            get { return nameSpace; }
            set { nameSpace = value; }
        }


        private bool _isEnabled;

        public bool IsEnabled
        {
            get { return _isEnabled; }
            set
            {
                SetProperty(ref _isEnabled, value);
            }
        }



        private Visibility _mainViewButtonVisible;

        public Visibility MainViewButtonVisible
        {
            get { return _mainViewButtonVisible; }
            set
            {
                SetProperty(ref _mainViewButtonVisible, value);
            }
        }


        private ObservableCollection<MenuBar> subItems;

        public ObservableCollection<MenuBar> SubItems
        {
            get { return subItems; }
            set
            {
                subItems = value;
                this.RaisePropertyChanged();
            }
        }

        private ICommand command;

        public ICommand Command
        {
            get { return command; }
            set
            {
                command = value;
                this.RaisePropertyChanged();
            }
        }
    }

　　

private void LoopItemsControl(object child)
{
ItemsControl itemsControl = child as ItemsControl;
for (int i = 0; i < itemsControl.Items.Count; i++)
{
DependencyObject dependencyObject = itemsControl.ItemContainerGenerator.ContainerFromIndex(i);
LoadControlsInXAMLContainer(dependencyObject);
LoopItemsControl(dependencyObject);
}

//if (child is ItemsControl)
//{
// ItemsControl itemsControl = child as ItemsControl;
// for (int i = 0; i < itemsControl.Items.Count; i++)
// {
// LoadControlsInXAMLContainer(itemsControl.ItemContainerGenerator.ContainerFromIndex(i));
// LoopItemsControl(itemsControl.ItemContainerGenerator.ContainerFromIndex(i));
// }

//}
}

 

foreach (object child in LogicalTreeHelper.GetChildren(dep))
{
if (child is ItemsControl)
{
LoopItemsControl(child);
//ItemsControl itemsControl = child as ItemsControl;
//for (int i = 0; i < itemsControl.Items.Count; i++)
//{
// DependencyObject dependencyObject = itemsControl.ItemContainerGenerator.ContainerFromIndex(i);
// LoadControlsInXAMLContainer(dependencyObject);
//}
//LoopItemsControl(child);
}
LoadControlsInXAMLContainer(child);
}

//修改后
    private void LoopItemsControl(object child)
    {
        ItemsControl itemsControl = child as ItemsControl;
        for (int i = 0; i < itemsControl.Items.Count; i++)
        {
                DependencyObject dependencyObject = itemsControl.ItemContainerGenerator.ContainerFromIndex(i);
                if (dependencyObject != null)
                {
                    //LoadControlsInXAMLContainer(dependencyObject);
                    DependencyObject dependencyObject1 = itemsControl.ItemContainerGenerator.ContainerFromIndex(0);
                    LoadControlsInXAMLContainer(dependencyObject1);

                    DependencyObject dependencyObject2 = ((ItemsControl) dependencyObject1).ItemContainerGenerator.ContainerFromIndex(i);

                    LoadControlsInXAMLContainer(dependencyObject2);

                    if (true)
                    {

                    }

                    //foreach (object items in LogicalTreeHelper.GetChildren(dependencyObject))
                    //{
                    //    LoadControlsInXAMLContainer(items);
                    //}
                }

            //LoopItemsControl(dependencyObject);

                    //for (int j = 0; i < VisualTreeHelper.GetChildrenCount(dependencyObject); j++)
                    //{
                    //    var child1 = VisualTreeHelper.GetChild(dependencyObject, i);
                    //    LoadControlsInXAMLContainer(child1);
                    //}
         }
    }

ItemContainerGenerator.ContainerFromIndex(i) 是用来获取与 ItemsControl 的项关联的容器的。在许多情况下，例如 ListBox 或 ComboBox 等控件，这是获取实际元素的有效方式。

然而，对于 Menu 和 MenuItem，情况有些不同。MenuItem 的子项，即子菜单，不会立即生成其容器。当 MenuItem 首次展开时，WPF 才会为子项生成 MenuItem 容器。如果你试图在 MenuItem 首次展开之前使用 ItemContainerGenerator.ContainerFromIndex(i) ，你可能会收到 null，因为子 MenuItem 的容器还没有被生成。

因此，对于 MenuItem，最可靠的方式是直接遍历其 Items 集合，就像我在之前的回答中所展示的那样。这将确保你能访问所有子 MenuItem，无论它们的容器是否已被生成。

这是 WPF 菜单系统的一种特性，以提高性能。只有当用户实际需要看到或交互 with 子菜单时，WPF 才会为其生成容器。