/// <summary>
        /// 连接读卡器
        /// </summary>
        /// <param name="msg">输出信息</param>
        /// <returns>是否成功</returns>
        public override bool DevOpen(out string msg)
        {
            msg = "读卡器连接成功!";
            bool res = true;
            int  st  = 0;

            st = ReaderDllMethod.mwDevOpen("USB", "", out handle); //打开读写器
            if (st < 0)
            {
                msg = ReaderDllMethod.getErrMsg(st);
                res = false;
            }
            else
            {
                DevBeep(1, 1, 3);
            }
            return(res);
        }