读取硬盘SN

private String GetHardDiskID() {
            try {
                ManagementClass searcher = new ManagementClass("Win32_PhysicalMedia");
                ManagementObjectCollection moc = searcher.GetInstances();
                String strHardDiskID = "";
                foreach (ManagementObject mo in moc) {
                    strHardDiskID = mo["SerialNumber"].ToString().Trim();
                    break;
                }
                return strHardDiskID;
            } catch (Exception ex) {
                MessageBox.Show(ex.Message);
                return "";
            }
        }