XML文档的基本操作（一）

已知有一个XML文档（bookstore.xml）如下：


<?xml version="1.0" encoding="gb2312"?>
<bookstore>
<book genre="fantasy" ISBN="2-3631-4">
<title>Oberons Legacy</title>
<author>Corets, Eva</author>
<price>5.95</price>
</book>
</bookstore>

1、往<bookstore>节点中插入一个<book>节点：

XmlDocument xmlDoc=new XmlDocument();
xmlDoc.Load("bookstore.xml");
XmlNode root=xmlDoc.SelectSingleNode("bookstore");//查找<bookstore>
XmlElement xe1=xmlDoc.CreateElement("book");//创建一个<book>节点
xe1.SetAttribute("genre","李赞红");//配置该节点genre属性
xe1.SetAttribute("ISBN","2-3631-4");//配置该节点ISBN属性

XmlElement xesub1=xmlDoc.CreateElement("title");
xesub1.InnerText="CS从入门到精通";//配置文本节点
xe1.AppendChild(xesub1);//添加到<book>节点中
XmlElement xesub2=xmlDoc.CreateElement("author");
xesub2.InnerText="候捷";
xe1.AppendChild(xesub2);
XmlElement xesub3=xmlDoc.CreateElement("price");
xesub3.InnerText="58.3";
xe1.AppendChild(xesub3);

root.AppendChild(xe1);//添加到<bookstore>节点中
xmlDoc.Save("bookstore.xml");


//================
结果为：



<?xml version="1.0" encoding="gb2312"?>
<bookstore>
<book genre="fantasy" ISBN="2-3631-4">
<title>Oberons Legacy</title>
<author>Corets, Eva</author>
<price>5.95</price>
</book>
<book genre="李赞红" ISBN="2-3631-4">
<title>CS从入门到精通</title>
<author>候捷</author>
<price>58.3</price>
</book>
</bookstore>



2、修改节点：将genre属性值为“李赞红“的节点的genre值改为“update李赞红”，将该节点的子节点<author>的文本修改为“亚胜”。


XmlNodeList nodeList=xmlDoc.SelectSingleNode("bookstore").ChildNodes;//获取bookstore节点的任何子节点
foreach(XmlNode xn in nodeList)//遍历任何子节点
{
XmlElement xe=(XmlElement)xn;//将子节点类型转换为XmlElement类型
if(xe.GetAttribute("genre")=="李赞红")//假如genre属性值为“李赞红”
{
xe.SetAttribute("genre","update李赞红");//则修改该属性为“update李赞红”

XmlNodeList nls=xe.ChildNodes;//继续获取xe子节点的任何子节点
foreach(XmlNode xn1 in nls)//遍历
{
XmlElement xe2=(XmlElement)xn1;//转换类型
if(xe2.Name=="author")//假如找到
{
xe2.InnerText="亚胜";//则修改
break;//找到退出来就能够了
}
}
break;
}
}

xmlDoc.Save("bookstore.xml");//保存。



//=================

最后结果为：


<?xml version="1.0" encoding="gb2312"?>
<bookstore>
<book genre="fantasy" ISBN="2-3631-4">
<title>Oberons Legacy</title>
<author>Corets, Eva</author>
<price>5.95</price>
</book>
<book genre="update李赞红" ISBN="2-3631-4">
<title>CS从入门到精通</title>
<author>亚胜</author>
<price>58.3</price>
</book>
</bookstore>



3、删除 <book genre="fantasy" ISBN="2-3631-4">节点的genre属性，删除 <book genre="update李赞红" ISBN="2-3631-4">节点。


XmlNodeList xnl=xmlDoc.SelectSingleNode("bookstore").ChildNodes;

foreach(XmlNode xn in xnl)
{
XmlElement xe=(XmlElement)xn;


if(xe.GetAttribute("genre")=="fantasy")
{
xe.RemoveAttribute("genre");//删除genre属性
}
else if(xe.GetAttribute("genre")=="update李赞红")
{
xe.RemoveAll();//删除该节点的全部内容
}
}
xmlDoc.Save("bookstore.xml");

//====================

最后结果为：


<?xml version="1.0" encoding="gb2312"?>
<bookstore>
<book ISBN="2-3631-4">
<title>Oberons Legacy</title>
<author>Corets, Eva</author>
<price>5.95</price>
</book>
<book>
</book>
</bookstore>


4、显示任何数据。


XmlNode xn=xmlDoc.SelectSingleNode("bookstore");

XmlNodeList xnl=xn.ChildNodes;

foreach(XmlNode xnf in xnl)
{
XmlElement xe=(XmlElement)xnf;
Console.WriteLine(xe.GetAttribute("genre"));//显示属性值
Console.WriteLine(xe.GetAttribute("ISBN"));

XmlNodeList xnf1=xe.ChildNodes;
foreach(XmlNode xn2 in xnf1)
{
Console.WriteLine(xn2.InnerText);//显示子节点点文本
}
}



public static string DataToXml(string _ip,string _xmlType,bool _issavexml,string _contenttype,string _message,string _sendtime,string _toip)
        {
            //return null;
            DataParser dp = new DataParser();
            dp.Message = _message;
            dp.IP = _ip;
            dp.XmlType = _xmlType;
            dp.isSaveXml = _issavexml;
            dp.ContentType = _contenttype;
            dp.Sendtime = _sendtime;
            dp.Toip = _toip;
            XmlDocument doc = new XmlDocument();
            XmlDeclaration newDec = doc.CreateXmlDeclaration("1.0",null,null);
            doc.AppendChild(newDec);
            XmlElement newRoot = doc.CreateElement("Requests");
            doc.AppendChild(newRoot);
            XmlElement newtitle = doc.CreateElement("Request");
            newtitle.SetAttribute("time", dp.Sendtime);
            newRoot.AppendChild(newtitle);
            XmlElement from = doc.CreateElement("from");
            from.SetAttribute("ip", dp.IP);
            from.SetAttribute("type", dp.XmlType);
            from.SetAttribute("ctntype", dp.ContentType);
            XmlNode xnfrom = doc.CreateNode(XmlNodeType.CDATA, "content", null);
            xnfrom.InnerText = _message;
            from.PrependChild(xnfrom);
          // from.InnerText = _message;
            newtitle.AppendChild(from);
            XmlElement to = doc.CreateElement("to");
            (to as XmlElement).SetAttribute("ip", dp.Toip);
            newtitle.AppendChild(to);
            return doc.OuterXml;
        }

        /// <summary>
        /// 数据解包
        /// 将xml解析成UserConnection对象
        /// </summary>
        /// <returns>UserConnection</returns>
        public static DataParser[] XmlToData(string outxml)
        {
            //return null;
            DataParser[] dp = null;
            try
            {
                XmlDocument doc = new XmlDocument();
                doc.LoadXml(outxml);
                XmlNode rootnode = doc.SelectSingleNode("Requests");
                XmlNodeList bodynodelist = rootnode.SelectNodes("Request");
                dp = new DataParser[bodynodelist.Count];
                foreach (XmlNode sn in bodynodelist)
                {
                    int i = 0;
                    XmlElement xe = (XmlElement)sn;
                    XmlNode xn = sn.SelectSingleNode("from");
                    dp[i] = new DataParser();
                    dp[i].IP = (xn as XmlElement).Attributes["ip"].Value;
                   
                  // dp[i].IP = (xn as XmlElement).GetAttribute("ip");
                    dp[i].Message = xn.InnerText;
                    dp[i].ContentType = (xn as XmlElement).Attributes["ctntype"].Value;
                    dp[i].XmlType = (xn as XmlElement).Attributes["type"].Value;
                    dp[i].Sendtime = (sn as XmlElement).Attributes["time"].Value;
                    XmlNode xn2 = sn.SelectSingleNode("to");
                    dp[i].Toip = (xn2 as XmlElement).Attributes["ip"].Value;
                    i++;

                }


            }
            catch (Exception err)
            {
                ChatCommon.Common.ExceptionHand.HandleErr(err.ToString());
            }
            return dp;
        }



using System;
using System.Collections.Generic;
using System.Text;
using System.Xml;
namespace XmlDOM
{
    class Program
    {
        static void Main(string[] args)
        {
            XmlDocument doc = new XmlDocument();
            XmlDeclaration xd = doc.CreateXmlDeclaration("1.0", null, null);
            doc.AppendChild(xd);
            XmlElement xe = doc.CreateElement("bookstore");
            doc.AppendChild(xe);
            XmlElement xr = doc.CreateElement("book");
            xr.SetAttribute("publish", "thinkbank+1");
            xr.InnerText = "c#基础";
            xe.AppendChild(xr);
            XmlElement xr2 = doc.CreateElement("book");
            xr2.SetAttribute("publish", "thinkbank+1");
            xr2.InnerText = "j#基础";
            xe.AppendChild(xr2);
            string xml = doc.OuterXml;
            XmlDocument doc2 = new XmlDocument();
            doc2.LoadXml(xml);
            //doc.Save(@"d:/33.xml");
            //XmlDocument doc = new XmlDocument();
            //doc.Load(@"d:/33.xml");
            ////XmlNode xn = doc.SelectSingleNode("bookstore");
            XmlNodeList xnlist = doc2.SelectNodes("//book");
            foreach (XmlNode mynode in xnlist)
            {
                Console.WriteLine(mynode.InnerText);
            }
          
        }
    }
}