/// <summary>
        /// 获取机器guid
        /// </summary>
        /// using System.Management;  // 需要添加System.Management的引用 
        /// <returns></returns>
        public static string GetMachineGuid()
        {
            string location = @"SOFTWARE\Microsoft\Cryptography";
            string name = "MachineGuid";

            using (var classesRootKey = Microsoft.Win32.RegistryKey.OpenBaseKey(Microsoft.Win32.RegistryHive.LocalMachine, Microsoft.Win32.RegistryView.Registry64))
            {
                using (var regKey = classesRootKey.OpenSubKey(location))
                {
                    if (regKey != null)
                    {
                        var machineGuid = regKey.GetValue(name);
                        if (machineGuid != null)
                        {
                            return machineGuid.ToString();
                        }
                    }
                }
            }
            return null;
        }