XML和DataTable相互转换

//XML转DataSet
public static void XmlToDataTableByFile(){
            XmlDocument doc = new XmlDocument();
            doc.Load(@"E:\\xmlsample.xml");
            DataSet ds = new DataSet();
            StringReader tr = new StringReader(doc.InnerXml);      
            //DataTable也可以ReadXml()      
            ds.ReadXml(tr);
}   
//DataSet转XML  
public static void DataTableToXml(){
            //获取DataSet数据
            DataSet ds = XmlToDataTableByFile();
            StringWriter sw = new StringWriter();
            ds.Tables[0].WriteXml(sw);
            //XML字符串
            string XmlStr =sw.ToString();
}