1 public string GetRandStr() 2         { 3             System.Text.StringBuilder newRandom = new System.Text.StringBuilder(20); 4             Random rd = new Random(); 5             char[] dptSysID = { ‘0‘, ‘1‘, ‘2‘, ‘3‘, ‘4‘, ‘5‘, ‘6‘, ‘7‘, ‘8‘, ‘9‘, ‘a‘, ‘c‘, ‘d‘, ‘e‘, ‘A‘, ‘B‘, ‘C‘, ‘D‘, ‘E‘, ‘F‘ }; 6             for (int i = 0; i < 32; i++) 7             { 8                 newRandom.Append(dptSysID[rd.Next(20)]); 9             }10             string sysID = newRandom.ToString();11             return sysID.Substring(0, 8).ToString() + "-"12                  + sysID.Substring(8, 4).ToString() + "-"13                  + sysID.Substring(12,4).ToString() + "-"14                  + sysID.Substring(16,4).ToString() + "-"15                  + sysID.Substring(20,12).ToString();16         }