/// <summary>        /// 获得当前机器的活动中Mac地址，若无联网则返回空""        /// 需在项目引用中添加 System.Management        /// </summary>        /// <returns>mac地址，例如：00-00-00-00-00-00</returns>        public static string GetNetworkAdpaterID()        {            try            {                string mac = "";                ManagementClass mc = new ManagementClass("Win32_NetworkAdapterConfiguration");                ManagementObjectCollection moc = mc.GetInstances();                foreach (ManagementObject mo in moc)                    if ((bool)mo["IPEnabled"] == true)                    {                        mac = mo["MacAddress"].ToString();                        break;                    }                moc = null;                mc = null;                return mac.Trim().Replace(‘:‘, ‘-‘);            }            catch (Exception e)            {                return "error:" + e.Message;            }        }