A utility class for hiding checkboxes on specific TreeNodse

TreeNodeCheckBoxUtil.cs

using System;
using System.Runtime.InteropServices 

namespace WinformUtils 
{
    /// <summary>
    /// A utility class for hiding checkboxes on 
    /// specific TreeNodes
    /// </summary>
    /// <author>
    /// C# Port and Wrapping (Daniel Kuschny)
    /// Based on Claes Bergefalls VB.net version: 
    /// https://groups.google.com/group/microsoft.public.dotnet.framework.windowsforms/browse_thread/thread/cae78920cb6ff461/0a0b6b7c0571018c
    /// </author>
    public class TreeNodeCheckBoxUtil 
    {

        private const int TVIF_STATE = 0x8;
        private const int TVIS_STATEIMAGEMASK = 0xf000;
        private const int TV_FIRST = 0x1100;
        private const int TVM_SETITEM = TV_FIRST + 63;

        private struct TVITEM 
        {
          public uint mask;
          public IntPtr hItem;
          public uint state;
          public uint stateMask;
          public IntPtr pszText;
          public int cchTextMax;
          public int iImage;
          public int iSelectedImage;
          public int cChildren;
          public IntPtr lParam;
        }

        [DllImport("user32.dll")]
        private static extern IntPtr SendMessage(IntPtr hWnd, int Msg, IntPtr wParam, IntPtr lParam);
        
        private const int CHECKBOX_HIDDEN_INDEX = 0;
        
        /// <summary>
        /// Hides the CheckBox on the specified node. 
        /// </summary>
        /// <param name="node">The node on which to hide the CheckBox</param>        
        public static void HideCheckBox(TreeNode node) 
        {
            // setting the image state index to 0 
            // hides the checkbox 
            TVITEM tvi = new TVITEM();
            tvi.hItem = node.Handle;
            tvi.mask = TVIF_STATE;
            tvi.stateMask = TVIS_STATEIMAGEMASK;
            tvi.state = CHECKBOX_HIDDEN_INDEX << 12;
            SendMessage(node.TreeView.Handle, TVM_SETITEM, IntPtr.Zero, tvi);
        }
    }
}