C#注册系统全局快捷键

int keyid = 10;
        Dictionary<int, HotKeyCallBackHanlder> keymap = new Dictionary<int, HotKeyCallBackHanlder>();
        public delegate void HotKeyCallBackHanlder();
        public enum HotkeyModifiers
        {
            Alt = 1,
            Control = 2,
            Shift = 4,
            Win = 8
        }
        [System.Runtime.InteropServices.DllImport("user32.dll")]
        static extern bool RegisterHotKey(IntPtr hWnd, int id, int modifiers, System.Windows.Forms.Keys vk);
        [System.Runtime.InteropServices.DllImport("user32.dll")]
        static extern bool UnregisterHotKey(IntPtr hWnd, int id);
        /// <summary>
        /// 注册快捷键
        /// </summary>
        /// <param name="hWnd">持有快捷键窗口的句柄</param>
        /// <param name="modifiers">组合键</param>
        /// <param name="vk">快捷键的虚拟键码</param>
        /// <param name="callBack">回调函数（按下快捷键时被调用的方法）</param>
        public void Regist(IntPtr hWnd, int modifiers, System.Windows.Forms.Keys vk, HotKeyCallBackHanlder callBack)
        {
            int id = keyid++;
            if (!RegisterHotKey(hWnd, id, modifiers, vk))
                throw new Exception("注册失败！");
            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 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 void ProcessHotKey(System.Windows.Forms.Message m)
        {
            if (m.Msg == 0x312)
            {
                int id = m.WParam.ToInt32();
                HotKeyCallBackHanlder callback;
                if (keymap.TryGetValue(id, out callback))
                    callback();
            }
        }

  HotKeys hotKsys = new HotKeys();

        private void Form1_Load(object sender, EventArgs e)
        {
            hotKsys.Regist(this.Handle, (int)HotKeys.HotkeyModifiers.Control + (int)HotKeys.HotkeyModifiers.Alt, Keys.H, CallBack_Hide);//Ctrl+Alt+H
            hotKsys.Regist(this.Handle, (int)HotKeys.HotkeyModifiers.Control, Keys.W, CallBack_Show);//Ctrl+W
        }

        void CallBack_Hide()
        {
            this.Hide();
        }

        void CallBack_Show()
        {
            this.Show();
        }

        protected override void WndProc(ref Message m)
        {
            hotKsys.ProcessHotKey(m);
            base.WndProc(ref m);
        }

        private void Form1_FormClosing(object sender, FormClosingEventArgs e)
        {
            hotKsys.UnRegist(this.Handle, CallBack_Hide);
            hotKsys.UnRegist(this.Handle, CallBack_Show);
        }