c# 操作XML

c# 操作XML
XML文件
<?xml version="1.0" encoding="utf-8"?>
<booklist>
  <book>
    <name>历史</name>
    <auther>陈平</auther>
    <pubdate>2009-6-7</pubdate>
  </book>
  <book ids="chen">
    <name>历史</name>
    <auther>chen ping</auther>
  </book> 
</booklist>
使用的命名空间：
using System.Xml;
//遍历
   string strxml = "";
            XmlDocument xmldoc = new XmlDocument();
            xmldoc.Load(Server.MapPath(@"book.xml"));
            XmlNodeList xmllist = xmldoc.SelectNodes("booklist/book");
            foreach (XmlNode xn in xmllist)
            {
                strxml += xn["name"].InnerText + xn["auther"].InnerText;
            }
            Response.Write(strxml);
//删除
   XmlNode xmldel = xmldoc.SelectSingleNode("booklist");
            XmlNodeList xmlist = xmldel.ChildNodes;
            foreach (XmlNode xns in xmlist)
            {
                if (xns["name"].InnerText == "PhotoShop")
                {
                    xmldel.RemoveChild(xns);
                    xmldoc.Save(Server.MapPath(@"book.xml"));
                }
                else
                {
                    xns["name"].InnerText = "历史";
                    xmldoc.Save(Server.MapPath(@"book.xml"));
                }
            }
//添加
XmlDocument xmldoc = new XmlDocument();
        xmldoc.Load(Server.MapPath(@"book.xml"));
        XmlNode root = xmldoc.SelectSingleNode("booklist");
        XmlElement xPortName = xmldoc.CreateElement("book");
        xPortName.SetAttribute("ids", "chen");  //添加属性
        XmlElement xSubNode1 = xmldoc.CreateElement("name");
        xSubNode1.InnerText = ".NET精通";
        xPortName.AppendChild(xSubNode1);
        XmlElement xSubNode2 = xmldoc.CreateElement("auther");
        xSubNode2.InnerText = "chen jian ping";
        xPortName.AppendChild(xSubNode2);
        root.AppendChild(xPortName);
        xmldoc.Save(Server.MapPath(@"book.xml"));