Question

Okay this may seem too simple of a question but I’ve wasted enough time looking for how to do this. I am using CE 6.5 on a mobile device and I have a ContextMenu with six MenuItems. When the Menu pops up the first Item in the list is automatically highlighted. I want to remove this highlight as it is confusing some of my users in thinking that it is the current state. I looked into ContextMenu and all its variables and MenuItem and haven’t found out how to remove automatic highlight of first item. Same goes for a MainMenu’s too.

Answer 1

I think the answer is, unfortunately, you can’t. I put in a strong effort this afternoon to get hold of that menu and I just couldn’t get a valid HMENU that the OS would allow me to use. If you want to continue trying to chase the path I was on the code is below, but I really think it’s a dead-end. At this point I’d consider P/Invoking everything for the menu (creation, population, etc) if you really need that feature.

using System;
using System.Linq;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Reflection;
using System.Runtime.InteropServices;

using UINT = System.UInt32;
using HMENU = System.IntPtr;
using HBITMAP = System.IntPtr;
using DWORD = System.UInt32;
using LPTSTR = System.IntPtr;

namespace MenuTest
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();

            contextMenu.MenuItems.Add(new MenuItem() { Text = "Item A" });
            contextMenu.MenuItems.Add(new MenuItem() { Text = "Item B" });
            contextMenu.MenuItems.Add(new MenuItem() { Text = "Item C" });
            contextMenu.MenuItems.Add(new MenuItem() { Text = "Item D" });

            this.MouseDown += new MouseEventHandler(Form1_MouseDown);
            contextMenu.Popup += new EventHandler(contextMenu_Popup);
        }

        void contextMenu_Popup(object sender, EventArgs e)
        {
            var type = contextMenu.GetType();
            var members = type.GetMembers(
                          BindingFlags.NonPublic | BindingFlags.Instance);
            var menuMember = type.GetField("m_hmnu", 
                             BindingFlags.NonPublic | BindingFlags.Instance);
            var hMenu = (HMENU)menuMember.GetValue(contextMenu);

            var info = new MENUITEMINFO();
            info.cbSize = (uint)Marshal.SizeOf(info);
            info.fMask = MIIM_STATE;
            var result = GetMenuItemInfo(hMenu, 0, true, out info);
            if (!result)
            {
                var err = Marshal.GetLastWin32Error();
                if (err == 0x0579) MessageBox.Show("Invalid menu handle");
                return;
            }
            info.fMask = MIIM_STATE;
            info.fState &= (~MFS_HILITE);
            result = SetMenuItemInfo(hMenu, 0, true, ref info); 
        }

        void Form1_MouseDown(object sender, MouseEventArgs e)
        {
            contextMenu.Show(this, new Point(e.X, e.Y));
        }

        private const uint MIIM_STATE = 1;
        private const uint MFS_UNHILITE = 0;
        private const uint MFS_HILITE = 0x80;        

        //typedef struct tagMENUITEMINFO {
        //  UINT cbSize; 
        //  UINT fMask; 
        //  UINT fType; 
        //  UINT fState; 
        //  UINT wID; 
        //  HMENU hSubMenu; 
        //  HBITMAP hbmpChecked; 
        //  HBITMAP hbmpUnchecked; 
        //  DWORD dwItemData; 
        //  LPTSTR dwTypeData; 
        //  UINT cch; 
        //} MENUITEMINFO, FAR* LPMENUITEMINFO; 
        private struct MENUITEMINFO
        {
            public UINT cbSize;
            public UINT fMask;
            public UINT fType;
            public UINT fState;
            public UINT wID;
            public HMENU hSubMenu;
            public HBITMAP hbmpChecked;
            public HBITMAP hbmpUnchecked;
            public DWORD dwItemData;
            public LPTSTR dwTypeData;
            public UINT cch; 
        }

        //BOOL SetMenuItemInfo(
        //  HMENU hMenu,
        //  UINT uItem,
        //  BOOL fByPosition,
        //  LPCMENUITEMINFO lpmii
        //);
        [DllImport("coredll", SetLastError = true)]
        private static extern bool SetMenuItemInfo(HMENU hMenu, UINT uItem, 
                                   [MarshalAs(UnmanagedType.Bool)]bool fByPosition, 
                                   ref MENUITEMINFO lpmii);

        //BOOL GetMenuItemInfo(
        //  HMENU hMenu,
        //  UINT uItem,
        //  BOOL fByPosition,
        //  LPMENUITEMINFO lpmii
        //);
        [DllImport("coredll", SetLastError = true)]
        private static extern bool GetMenuItemInfo(HMENU hMenu, UINT uItem, 
                                   [MarshalAs(UnmanagedType.Bool)]bool fByPosition, 
                                   out MENUITEMINFO lpmii);

        //HMENU GetSubMenu(
        //  HMENU hMenu,
        //  int nPos
        //);
        [DllImport("coredll", SetLastError = true)]
        private static extern HMENU GetSubMenu(HMENU hMenu, int nPos);
    }
}

EDIT

I knew I had code somewhere for doing all of this. We used to sell a commercial PopupMenu control that wrapped up all of the P/Invokes for menu creation. Sales for the control were small, so we pulled it from our product line a few years ago. I’ve now released it as open source over on Codeplex.