.NET Shell Extensions - Shell Context Menus

using System;

namespace SharpShell.Interop
{
    /// <summary>
    /// Contains information about a notification message.
    /// </summary>
    public struct NMHDR
    {
        /// <summary>
        /// A window handle to the control sending the message.
        /// </summary>
        public IntPtr hwndFrom;

        /// <summary>
        /// An identifier of the control sending the message.
        /// </summary>
        public UIntPtr idFrom;

        /// <summary>
        /// A notification code. This member can be one of the common notification codes (see Notifications under General Control Reference), or it can be a control-specific notification code.
        /// </summary>
        public uint code;
    }
}