/// <summary>
        /// 将DataSet对象转换成XML字符串
        /// </summary>        
        /// <returns>XML字符串</returns>
        public static string ToXml(DataSet ds)
        {
            if (ds == null) return string.Empty;

            MemoryStream ms = null;
            System.Xml.XmlTextWriter xmlWriter = null;

            int index = 1;
            foreach (DataTable dt in ds.Tables)
            {
                string tableName = dt.TableName;
                dt.TableName = String.IsNullOrWhiteSpace(tableName) ? "MyTableName" + index : tableName;
                index++;
            }

            try
            {  // 将DataTable转换为XML格式，并写入MemoryStream
                ms = new MemoryStream();
                xmlWriter = new XmlTextWriter(ms, Encoding.Unicode);

                ds.WriteXml(xmlWriter, XmlWriteMode.WriteSchema);
                xmlWriter.Flush();

                // 重置MemoryStream的位置，以便读取其内容
                ms.Position = 0;

                // 从MemoryStream读取XML内容
                StreamReader reader = new StreamReader(ms);
                string xmlContent = reader.ReadToEnd();

                // 关闭reader和memoryStream
                reader.Close();
                ms.Close();
                xmlWriter.Close();

                return xmlContent;
            }
            catch (System.Exception ex)
            {
                throw ex;
            }
            finally
            {
                //释放资源
                if (xmlWriter != null) xmlWriter.Close();
                if (ms != null) ms.Close();
            }

        }

        /// <summary>
        /// 将xml转换为dataset
        /// </summary>
        /// <param name="xml"></param>
        /// <returns></returns>
        public static DataSet FromXml(string xml)
        {
            StringReader stream = null;
            XmlTextReader reader = null;
            try
            {
                DataSet xmlDS = new DataSet();
                stream = new StringReader(xml);
                reader = new XmlTextReader(stream);
                xmlDS.ReadXml(reader);
                reader.Close();
                return xmlDS;
            }
            catch (System.Exception ex)
            {
                reader.Close();
                throw ex;
            }
        }