接收按键消息

 public const int WM_KEYDOWN = 0x0100;//按键消息
        public const int WM_SYSKEYDOWN = 0x0104;//快捷键或系统命令键的消息
        protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
        {if ((msg.Msg == WM_KEYDOWN) || (msg.Msg == WM_SYSKEYDOWN))
            {
               ///
            }
            return base.ProcessCmdKey(ref msg, keyData);
        }