/// <summary>
        /// 获取本机第一个索引的网卡MAC
        /// </summary>
        /// <returns></returns>
        public string GetMacAddress()
        {
            string mac = "";
            System.Management.ManagementClass mc;
            mc = new System.Management.ManagementClass("Win32_NetworkAdapterConfiguration");
            System.Management.ManagementObjectCollection moc = mc.GetInstances();
            foreach (System.Management.ManagementObject mo in moc)
            {
                //可以使用 mo.GetText(System.Management.TextFormat.Mof); 获取所有值

                if (mo["IPEnabled"].ToString().Equals("True"))
                {
                    ////IPSubnet = "255.255.255.255"，可能为拨号连接（MAC一般为:00-53-45-00-00-00）
                    if (mo["IPSubnet"] != null)
                    {
                        //记录是否为无效地址
                        bool isInvalid = false;string[] ipSubnets = (string[])mo["IPSubnet"];
                        foreach (string ipSubnet in ipSubnets)
                        {
                            if (ipSubnet.Equals("255.255.255.255"))
                            {
                                isInvalid = true;
                                break;
                            }
                        }if (!isInvalid)
                        {
                            //获取第一个MAC
                            mac = mo["MacAddress"].ToString();
                            break;
                        }
                    }                    
                }
            }return mac;
        }