xml与DataSet的互转换类

以前在博客上发过，经人提醒DataSet已自带读写XML的功能，于是便删了，
不过在实践中感觉封装一层后，使用起来还是蛮方便的。故再次重发。
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(Dat