using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml;
namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            XmlDocument doc = new XmlDocument();
            doc.LoadXml("<root>fdsa</root>");
            XmlElement root = doc.DocumentElement;
            XmlNodeList xnlist = root.ChildNodes;//获得根节点下的所有节点

            foreach(XmlNode xn in xnlist)
            {
                //遍历每一个节点
                string strText= xn.InnerText;//获得节点的值
                string strName = xn.Name;//获得节点的元素名称
                //..............................
            }
        }
    }
}

DataSet ds = new DataSet();
        byte[] byteArray = System.Text.Encoding.Unicode.GetBytes("<?xml version='1.0'?><roots><root><id>1</id><name>张三</name></root><root><id>1</id><name>张三</name></root></roots>");
        System.IO.MemoryStream stream = new System.IO.MemoryStream(byteArray);
        ds.ReadXml(stream);
        DataTable dt = ds.Tables[0];