XmlDatasetConvert 该类提供了四种方法：

1、将xml对象内容字符串转换为DataSet

2、将xml文件转换为DataSet

3、将DataSet转换为xml对象字符串

4、将DataSet转换为xml文件

XmlDatasetConvert.cs

using System;

using System.Collections.Generic;

using System.Text;

using System.Data;

using System.IO;

using System.Xml;

namespace XmlDesign

{

    class XmlDatasetConvert

    {

        //将xml对象内容字符串转换为DataSet

        public static DataSet ConvertXMLToDataSet(string xmlData)

        {

            StringReader stream = null;

            XmlTextReader reader = null;

            try

            {

                DataSet xmlDS = new DataSet();

                stream = new StringReader(xmlData);

                //从stream装载到XmlTextReader

                reader = new XmlTextReader(stream);

                xmlDS.ReadXml(reader);

                return xmlDS;

            }

            catch (System.Exception ex)

            {

                throw ex;

            }

            finally

            {

                if (reader != null) reader.Close();

            }

        }

        //将xml文件转换为DataSet

        public static DataSet ConvertXMLFileToDataSet(string xmlFile)

        {

            StringReader stream = null;

            XmlTextReader reader = null;

            try

            {

                XmlDocument xmld = new XmlDocument();

                xmld.Load(xmlFile);

                DataSet xmlDS = new DataSet();

                stream = new StringReader(xmld.InnerXml);

                //从stream装载到XmlTextReader

                reader = new XmlTextReader(stream);

                xmlDS.ReadXml(reader);

                //xmlDS.ReadXml(xmlFile);

                return xmlDS;

            }

            catch (System.Exception ex)

            {

                throw ex;

            }

            finally

            {

                if (reader != null) reader.Close();

            }

        }

        //将DataSet转换为xml对象字符串

        public static string ConvertDataSetToXML(DataSet xmlDS)

        {

            MemoryStream stream = null;

            XmlTextWriter writer = null;

            try

            {

                stream = new MemoryStream();

                //从stream装载到XmlTextReader

                writer = new XmlTextWriter(stream, Encoding.Unicode);

                //用WriteXml方法写入文件.

                xmlDS.WriteXml(writer);

                int count = (int)stream.Length;

                byte[] arr = new byte[count];

                stream.Seek(0, SeekOrigin.Begin);

                stream.Read(arr, 0, count);

                UnicodeEncoding utf = new UnicodeEncoding();

                return utf.GetString(arr).Trim();

            }

            catch (System.Exception ex)

            {

                throw ex;

            }

            finally

            {

                if (writer != null) writer.Close();

            }

        }

        //将DataSet转换为xml文件

        public static void ConvertDataSetToXMLFile(DataSet xmlDS,string xmlFile)

        {

            MemoryStream stream = null;

            XmlTextWriter writer = null;

            try

            {

                stream = new MemoryStream();

                //从stream装载到XmlTextReader

                writer = new XmlTextWriter(stream, Encoding.Unicode);

                //用WriteXml方法写入文件.

                xmlDS.WriteXml(writer);

                int count = (int)stream.Length;

                byte[] arr = new byte[count];

                stream.Seek(0, SeekOrigin.Begin);

                stream.Read(arr, 0, count);

                //返回Unicode编码的文本

                UnicodeEncoding utf = new UnicodeEncoding();

                StreamWriter sw = new StreamWriter(xmlFile);

                sw.WriteLine("<?xml version=\"1.0\" encoding=\"utf-8\"?>");

                sw.WriteLine(utf.GetString(arr).Trim());

                sw.Close();

            }

            catch( System.Exception ex )

            {

                throw ex;

            }

            finally

            {

                if (writer != null) writer.Close();

            }

        }

    }

}