根据Oracle客户端安装信息，添加Server名

在Oracle10g上测试过了，其它客户端应该差不多的。

            RegistryKey hklm = Registry.LocalMachine;
            RegistryKey hkSoftware = hklm.OpenSubKey("Software");
            RegistryKey hkOracle = hkSoftware.OpenSubKey("Oracle");
            if (hkOracle == null)
            {
                MessageBox.Show("未找到Oracle客户端安装路径信息。");
                return;
            }
            string OraClient = null;
            foreach (string tmp in hkOracle.GetSubKeyNames())
            {
                if (tmp.Contains("KEY_OraClient"))
                {
                    OraClient = tmp;
                    break;
                }
            }
            if (OraClient == null)
            {
                MessageBox.Show("未找到Oracle客户端安装路径信息。");
                return;
            }

            String path = (string)hkOracle.OpenSubKey(OraClient).GetValue("ORACLE_HOME");
            string tns = File.ReadAllText(Path.Combine(path, @"NETWORK\ADMIN\tnsnames.ora"));
            if (!Regex.IsMatch(tns, @"(?s)km\s*=\s*\(.+\)"))
                tns += @"
km =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = 10.0.192.23)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = km)
    )
  )
";
            File.WriteAllText(Path.Combine(path, @"NETWORK\ADMIN\tnsnames.ora"), tns);