获取客户端MAC

有时候我们需要获取客户端的一些信息来做处理，获取mac，代码如下

        [DllImport("Iphlpapi.dll")]
        private static extern int SendARP(Int32 dest, Int32 host, ref Int64 mac, ref Int32 length);
        [DllImport("Ws2_32.dll")]
        private static extern Int32 inet_addr(string ip);

        //获取mac
        public static string GetMac()
        {
            string strMac = string.Empty;
            try
            {
                string strClientIP = GetClientIPv4();
                Int32 ldest = inet_addr(strClientIP); //目的地的ip
                Int32 lhost = inet_addr("");   //本地服务器的ip
                Int64 macinfo = new Int64();
                Int32 len = 6;
                int res = SendARP(ldest, 0, ref macinfo, ref len);
                string mac_src = macinfo.ToString("X");
                if (mac_src == "0")
                {
                    return strMac;
                }

                while (mac_src.Length < 12)
                {
                    mac_src = mac_src.Insert(0, "0");
                }

                string mac_dest = "";

                for (int i = 0; i < 11; i++)
                {
                    if (0 == (i % 2))
                    {
                        if (i == 10)
                        {
                            mac_dest = mac_dest.Insert(0, mac_src.Substring(i, 2));
                        }
                        else
                        {
                            mac_dest = "-" + mac_dest.Insert(0, mac_src.Substring(i, 2));
                        }
                    }
                }

                strMac = mac_dest;
                return strMac;
            }
            catch (Exception err)
            {
                throw err;
            }
        }