/// <summary>
        /// datatable转换xml
        /// </summary>
        /// <param name="xmlDS"></param>
        /// <returns></returns>
        public static string ConvertDataTableToXML(DataTable xmlDS)
        {
            StringBuilder strXml = new StringBuilder();
            strXml.AppendLine("<MonitorData>");
            for (int i = 0; i < xmlDS.Rows.Count; i++)
            {
                strXml.AppendLine("<" + xmlDS.TableName + ">");
                for (int j = 0; j < xmlDS.Columns.Count; j++)
                {
                    strXml.AppendLine("<" + xmlDS.Columns[j].ColumnName + ">" + xmlDS.Rows[i][j] + "</" + xmlDS.Columns[j].ColumnName + ">");
                }
                strXml.AppendLine("</" + xmlDS.TableName + ">");
            }
            strXml.AppendLine("</MonitorData>");

            return strXml.ToString();
        }