Total Commander里Help菜单在菜单栏右对齐的效果的实现方法

Total Commander里Help菜单在菜单栏右对齐的效果是什么原理，用C#怎么做？

如图：

 谢谢 游民一族 的指点，终于找到方法了。

        [StructLayout(LayoutKind.Sequential)]
        public class MenuItemInfo
        {
            public Int32 cbSize;
            public Int32 fMask;
            public Int32 fType;
            public Int32 fState;
            public Int32 wID;
            public IntPtr hSubMenu;
            public IntPtr hbmpChecked;
            public IntPtr hbmpUnchecked;
            public IntPtr dwItemData;
            public string dwTypeData;
            public Int32 cch;
        }

        [DllImport("user32.dll", CharSet = CharSet.Auto)]
        public static extern bool GetMenuItemInfo(
            HandleRef menuHandle,
            Int32 itemIndex,
            bool byPosition,
            [In, Out]MenuItemInfo menuItemInfo);

        [DllImport("user32.dll", CharSet = CharSet.Auto)]
        public static extern bool SetMenuItemInfo(
            HandleRef menuHandle,
            Int32 itemIndex,
            bool byPosition,
            MenuItemInfo menuItemInfo);

        const Int32 MIIM_FTYPE = 0x00000100;
        const Int32 MFT_RIGHTJUSTIFY = 0x00004000;

        public static void RightJustifyMenuItem(MenuItem menuItem)
        {
            HandleRef menuHandle = new HandleRef(menuItem.Parent, menuItem.Parent.Handle);
            MenuItemInfo menuItemInfo = new MenuItemInfo();
            menuItemInfo.cbSize = Marshal.SizeOf(typeof(MenuItemInfo));
            menuItemInfo.fMask = MIIM_FTYPE;
            GetMenuItemInfo(menuHandle, menuItem.Index, true, menuItemInfo);
            menuItemInfo.fType = menuItemInfo.fType | MFT_RIGHTJUSTIFY;
            SetMenuItemInfo(menuHandle, menuItem.Index, true, menuItemInfo);
        }

 

刚开始我把MenuItemInfo定义为struct，总是报Attempted to read or write protected memory的异常，搞了好半天才发现要用class。