XML 增、删、改和查示例

1.已知有一个XML文件（bookstore.xml）如下：

<?xml version="1.0" encoding="gb2312"?> <bookstore>   <book genre="fantasy" ISBN="2-3631-4">     <title>Oberon's 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");//设置该节点genre属性    xe1.SetAttribute("ISBN","2-3631-4");//设置该节点ISBN属性      XmlElement xesub1=xmlDoc.CreateElement("title");    xesub1.InnerText="CS从入门到精通";//设置文本节点    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>Oberon's 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节点的所有子节点    foreach(XmlNode xn in nodeList)//遍历所有子节点    {     XmlElement xe=(XmlElement)xn;//将子节点类型转换为XmlElement类型     if(xe.GetAttribute("genre")=="李赞红")//如果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子节点的所有子节点      foreach(XmlNode xn1 in nls)//遍历      {       XmlElement xe2=(XmlElement)xn1;//转换类型       if(xe2.Name=="author")//如果找到       {        xe2.InnerText="亚胜";//则修改        break;//找到退出来就可以了       }      }      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>Oberon's 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>Oberon's Legacy</title>     <author>Corets, Eva</author>     <price>5.95</price>   </book>   <book>   </book> </bookstore>

 4、显示所有数据。

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     }    }

留做参考,原文地址http://blog.yesky.com/75/richsee/1211075.shtml

2前台代码：html

<% @ Page language="c#" Codebehind="Main.aspx.cs" AutoEventWireup="false" Inherits="DsAndXML.OpXMLFile.Main"  %>
<! DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"  >
< HTML >
     < HEAD >
         < title > Main </ title >
         < meta  name ="GENERATOR"  Content ="Microsoft Visual Studio 7.0" >
         < meta  name ="CODE_LANGUAGE"  Content ="C#" >
         < meta  name ="vs_defaultClientScript"  content ="JavaScript" >
         < meta  name ="vs_targetSchema"  content ="http://schemas.microsoft.com/intellisense/ie5" >
     </ HEAD >
     < body  MS_POSITIONING ="GridLayout" >
         < form  id ="Main"  method ="post"  runat ="server" >
             < FONT  face ="宋体" >
                 < asp:DataGrid  id ="dgShow"  style ="Z-INDEX: 100; LEFT: 113px; POSITION: absolute; TOP: 32px"  runat ="server"  Width ="480px"  Height ="178px" ></ asp:DataGrid >
                 < asp:Label  id ="Label3"  style ="Z-INDEX: 111; LEFT: 187px; POSITION: absolute; TOP: 383px"  runat ="server"  Width ="120px"  Height ="21px" > 新邮件地址： </ asp:Label >
                 < asp:Label  id ="Label2"  style ="Z-INDEX: 107; LEFT: 333px; POSITION: absolute; TOP: 274px"  runat ="server"  Width ="83px"  Height ="21px" > 邮件地址： </ asp:Label >
                 < asp:Button  id ="btnAdd"  style ="Z-INDEX: 104; LEFT: 298px; POSITION: absolute; TOP: 324px"  runat ="server"  Text ="添加" ></ asp:Button >
                 < asp:Button  id ="btnDelete"  style ="Z-INDEX: 103; LEFT: 199px; POSITION: absolute; TOP: 324px"  runat ="server"  Text ="删除" ></ asp:Button >
                 < asp:Button  id ="btnChange"  style ="Z-INDEX: 102; LEFT: 102px; POSITION: absolute; TOP: 382px"  runat ="server"  Text ="修改" ></ asp:Button >
                 < asp:Button  id ="btnQuery"  style ="Z-INDEX: 101; LEFT: 101px; POSITION: absolute; TOP: 324px"  runat ="server"  Text ="查询" ></ asp:Button >
                 < asp:DropDownList  id ="ddlName"  style ="Z-INDEX: 105; LEFT: 210px; POSITION: absolute; TOP: 274px"  runat ="server"  Width ="95px"  Height ="78px" ></ asp:DropDownList >
                 < asp:Label  id ="Label1"  style ="Z-INDEX: 106; LEFT: 100px; POSITION: absolute; TOP: 274px"  runat ="server"  Width ="83px"  Height ="21px" > 姓名： </ asp:Label >
                 < asp:Label  id ="lbEmail"  style ="Z-INDEX: 109; LEFT: 459px; POSITION: absolute; TOP: 274px"  runat ="server"  Width ="231px" ></ asp:Label >
                 < asp:TextBox  id ="tbNewMail"  style ="Z-INDEX: 110; LEFT: 330px; POSITION: absolute; TOP: 381px"  runat ="server"  Width ="208px"  Height ="26px" ></ asp:TextBox ></ FONT >
         </ form >
     </ body >
</ HTML >

XML文件dbGuest.xml

<? xml version="1.0" standalone="yes" ?>
< dbGuest >
   < User >
     < Name > aaa </ Name >
     < City > shanghai </ City >
     < Email > [email protected] </ Email >
     < Message > ok </ Message >
     < STime > 2004-07-12T00:00:00.0000000+08:00 </ STime >
   </ User >
   < User >
     < Name > shaoazhd </ Name >
     < City > beijing </ City >
     < Email > [email protected] </ Email >
     < Message > afsa </ Message >
     < STime > 2004-7-12 15:07:39 </ STime >
   </ User >
   < User >
     < Name > Guset </ Name >
     < City > 上海 </ City >
     < Email > [email protected] </ Email >
   </ User >
   < User >
     < Name > Guset </ Name >
     < City > 上海 </ City >
     < Email > [email protected] </ Email >
   </ User >
</ dbGuest >

using  System;
using  System.Collections;
using  System.ComponentModel;
using  System.Data;
using  System.Drawing;
using  System.Web;
using  System.Web.SessionState;
using  System.Web.UI;
using  System.Web.UI.WebControls;
using  System.Web.UI.HtmlControls;
using  System.Xml;
using  System.Xml.XPath;
namespace  DsAndXML.OpXMLFile
{
    /**//// <summary>
    /// Main 的摘要说明。
    /// </summary>
    public class Main : System.Web.UI.Page
    {
        protected System.Web.UI.WebControls.Button btnQuery;
        protected System.Web.UI.WebControls.Button btnChange;
        protected System.Web.UI.WebControls.Button btnDelete;
        protected System.Web.UI.WebControls.Button btnAdd;
        protected System.Web.UI.WebControls.DropDownList ddlName;
        protected System.Web.UI.WebControls.Label Label1;
        protected System.Web.UI.WebControls.Label Label2;
        protected System.Web.UI.WebControls.Label lbEmail;
        protected System.Web.UI.WebControls.TextBox tbNewMail;
        protected System.Web.UI.WebControls.Label Label3;
        protected System.Web.UI.WebControls.DataGrid dgShow;
    
        private void Page_Load(object sender, System.EventArgs e)
        {
            // 在此处放置用户代码以初始化页面
            if(!IsPostBack)
            Bind();

        }
        private void Bind()
        {
            DataSet ds = new DataSet();
            ds.ReadXml(Server.MapPath(".\\db\\dbGuest.xml"));
            dgShow.DataSource = ds.Tables[0].DefaultView;
            dgShow.DataBind();
            XmlDocument doc = new XmlDocument();
            doc.Load(Server.MapPath(".\\db\\dbGuest.xml"));
            XmlNodeList elemList = doc.GetElementsByTagName("Name");
            ddlName.Items.Clear();
            for(int i=0;i<elemList.Count;i++)
             ddlName.Items.Add(elemList[i].InnerXml);
            
        }

        Web Form Designer generated code#region Web Form Designer generated code
        override protected void OnInit(EventArgs e)
        {
            //
            // CODEGEN：该调用是 ASP.NET Web 窗体设计器所必需的。
            //
            InitializeComponent();
            base.OnInit(e);
        }
        
        /**//// <summary>
        /// 设计器支持所需的方法 - 不要使用代码编辑器修改
        /// 此方法的内容。
        /// </summary>
        private void InitializeComponent()
        {    
            this.btnQuery.Click += new System.EventHandler(this.btnQuery_Click);
            this.btnChange.Click += new System.EventHandler(this.btnChange_Click);
            this.btnDelete.Click += new System.EventHandler(this.btnDelete_Click);
            this.btnAdd.Click += new System.EventHandler(this.btnAdd_Click);
            this.Load += new System.EventHandler(this.Page_Load);

        }
        #endregion

        private void btnQuery_Click(object sender, System.EventArgs e)
        {
            XmlDocument doc = new XmlDocument();
            doc.Load(Server.MapPath(".\\db\\dbGuest.xml"));
            lbEmail.Text = doc.SelectSingleNode("//User[Name='"+ddlName.SelectedItem.Text+"']").ChildNodes.Item(2).InnerText;
         
        }

        private void btnChange_Click(object sender, System.EventArgs e)
        {
            XmlDocument xmlDoc = new XmlDocument();
            xmlDoc.Load(Server.MapPath(".\\db\\dbGuest.xml"));
            XmlNodeList nodeList=xmlDoc.SelectSingleNode("dbGuest").ChildNodes;//获取dbGuest节点的所有子节点
            foreach(XmlNode xn in nodeList)//遍历所有子节点
            {
                XmlElement xe=(XmlElement)xn;//将子节点类型转换为XmlElement类型
            
                XmlNodeList node = xe.GetElementsByTagName("Name");
                if(node.Count>0)
                {

                    if(node[0].InnerText==ddlName.SelectedItem.Text)
                    {
                        XmlNodeList nls=xe.ChildNodes;//继续获取xe子节点的所有子节点
                        foreach(XmlNode xn1 in nls)//遍历
                        {
                            XmlElement xe2=(XmlElement)xn1;//转换类型
                            if(xe2.Name=="Email")//如果找到
                            {
                                xe2.InnerText=tbNewMail.Text;//则修改
                                break;//找到退出来就可以了
                            }
                        }
                        break;
                    }
                }
                
            }
            xmlDoc.Save(Server.MapPath(".\\db\\dbGuest.xml"));
            Bind();
        }

        private void btnDelete_Click(object sender, System.EventArgs e)
        {
            XmlDocument xmlDoc = new XmlDocument();
            xmlDoc.Load(Server.MapPath(".\\db\\dbGuest.xml"));
            XmlNodeList xnl=xmlDoc.SelectSingleNode("dbGuest").ChildNodes;
 
            foreach(XmlNode xn in xnl)
            {
                XmlElement xe=(XmlElement)xn;
                XmlNodeList node = xe.GetElementsByTagName("Name");
                if(node.Count>0)
                {

                    if(node[0].InnerText==ddlName.SelectedItem.Text)
                        xe.RemoveAll();//删除该节点的全部内容
                    break;
                }
            }
            
            xmlDoc.Save(Server.MapPath(".\\db\\dbGuest.xml"));
            Bind();
        }

        private void btnAdd_Click(object sender, System.EventArgs e)
        {
            XmlDocument xmlDoc = new XmlDocument();
            xmlDoc.Load(Server.MapPath(".\\db\\dbGuest.xml"));
            XmlNode root=xmlDoc.SelectSingleNode("dbGuest");//查找<dbGuest>
            XmlElement xe1=xmlDoc.CreateElement("User");//创建一个<User>节点
            XmlElement xesub1=xmlDoc.CreateElement("Name");
            xesub1.InnerText="Guset";//设置文本节点
            xe1.AppendChild(xesub1);//添加到<User>节点中
            XmlElement xesub2=xmlDoc.CreateElement("City");
            xesub2.InnerText="上海";
            xe1.AppendChild(xesub2);
            XmlElement xesub3=xmlDoc.CreateElement("Email");
            xesub3.InnerText="[email protected]";
            xe1.AppendChild(xesub3);
 
            root.AppendChild(xe1);//添加到<dbGuest>节点中
            xmlDoc.Save(Server.MapPath(".\\db\\dbGuest.xml"));
            Bind();
        }
    }
}

转自 http://www.cnblogs.com/skylaugh/archive/2006/12/18/595634.html