public override bool Request(out string msg)
        {
            bool   res = true;
            int    st  = 0;
            ushort cardtype;

            st = ReaderDllMethod.mwRequest(handle, Mode, out cardtype); //请求卡TYPE A 类型卡片
            if (st < 0)
            {
                msg = st.ToString() + "*" + ReaderDllMethod.getErrMsg(st);
                res = false;
            }
            else
            {
                msg      = st.ToString() + "*" + ReaderDllMethod.getErrMsg(st);
                CardType = cardtype;
                DevBeep(1, 1, 2);
            }
            return(res);
        }