本文来自CSDN博客，转载请标明出处：http://blog.csdn.net/ismycxp/archive/2007/07/19/1698942.aspx

附上一个注册热键的类

用其他朋友的整理的，出处作者不明。

using System.Runtime.InteropServices;
using System;
using System.Windows.Forms;
using System.Collections.Generic;
namespace AFLib.Base
{
    public delegate void HotKeyCallBackHanlder();
    /// <summary>
    /// 使用步骤：
    /// 1、在窗体加载时，使用Regist注册热键
    /// 2、重载WndProc方法，使用ProcessHotKey，用于实现热键响应。  
    /// base.WndProc(ref m);
    /// Hotkey.ProcessHotKey(m);
    /// 3、在窗体关闭时，必须使用UnRegist注销热键。
    /// </summary>
    public class Hotkey
    {
        #region 系统api
        [DllImport("user32.dll")]
        [return: MarshalAs(UnmanagedType.Bool)]
        static extern bool RegisterHotKey(IntPtr hWnd, int id, HotkeyModifiers fsModifiers, Keys vk);

        [DllImport("user32.dll")]
        static extern bool UnregisterHotKey(IntPtr hWnd, int id);

        [System.Runtime.InteropServices.DllImport("user32.dll")] //申明API函数
        public static extern bool RegisterHotKey(
        IntPtr hWnd, // handle to window
        int id, // hot key identifier
        uint fsModifiers, // key-modifier options
        Keys vk // virtual-key code
        );

        #endregion

        const int WM_HOTKEY = 0x312;
        static int keyid = 10;
        static Dictionary<int, HotKeyCallBackHanlder> keymap = new Dictionary<int, HotKeyCallBackHanlder>();

        /// <summary>
        /// 注册快捷键
        /// </summary>
        /// <param name="hWnd">持有快捷键窗口的句柄</param>
        /// <param name="fsModifiers">组合键</param>
        /// <param name="vk">快捷键的虚拟键码</param>
        /// <param name="callBack">回调函数</param>
        public static void Regist(IntPtr hWnd, HotkeyModifiers fsModifiers, Keys vk, HotKeyCallBackHanlder callBack)
        {
            int id = keyid++;
            if (!RegisterHotKey(hWnd, id, fsModifiers, vk))
                MessageBox.Show("暂时热键不可用！", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
            keymap[id] = callBack;
        }

        public static void Regist(IntPtr hWnd, uint fsModifiers, Keys vk, HotKeyCallBackHanlder callBack)
        {
            int id = keyid++;
            if (!RegisterHotKey(hWnd, id, fsModifiers, vk))
                MessageBox.Show("暂时热键不可用！", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
            keymap[id] = callBack;
        }

        /// <summary>
        /// 注销快捷键
        /// </summary>
        /// <param name="hWnd">持有快捷键窗口的句柄</param>
        /// <param name="callBack">回调函数</param>
        public static void UnRegist(IntPtr hWnd, HotKeyCallBackHanlder callBack)
        {
            foreach (KeyValuePair<int, HotKeyCallBackHanlder> var in keymap)
            {
                if (var.Value == callBack)
                    UnregisterHotKey(hWnd, var.Key);
            }
        }

        /// <summary>
        /// 快捷键消息处理
        /// </summary>
        public static void ProcessHotKey(System.Windows.Forms.Message m)
        {
            if (m.Msg == WM_HOTKEY)
            {
                int id = m.WParam.ToInt32();
                HotKeyCallBackHanlder callback;
                if (keymap.TryGetValue(id, out callback))
                {
                    callback();
                }
            }
        }

        /// <summary>
        /// 将字符转换为键值,如果转换失败,则返回指定的值
        /// </summary>
        /// <param name="s"></param>
        /// <returns></returns>
        public static Keys ParseToKey(string s, Keys key)
        {
            try
            {
                Keys k = (Keys)Enum.Parse(typeof(Keys), s.ToUpper());
                return k;
            }
            catch
            {
                return key;
            }
        }
    }

    public enum HotkeyModifiers
    {
        MOD_None = 0x0,
        MOD_Alt = 0x1,
        MOD_Ctrl = 0x2,
        MOD_Shift = 0x4,
        MOD_WindowsKey = 0x8
    }
}