xml与DataSet互转

//将DataSet转换为xml字符串
   public static string ConvertDataSetToXMLFile(DataSet xmlDS, Encoding encoding)
   {
       MemoryStream stream = null; XmlTextWriter writer = null;
       string result = "<result>-3</result>";
       try
       {
           stream = new MemoryStream();
           //从stream装载到XmlTextReader
           writer = new XmlTextWriter(stream, encoding);
           //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);
           result = "<?xml version="1.0" encoding="utf-8"?>" + encoding.GetString(arr).Trim();
       }
       catch { }
       finally
       {
           if (writer != null) writer.Close();
       }
       return result;
   }

//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();
           }
       }

转载自：https://blog.51cto.com/aonaufly/1298823