XML 增、删、改和查示例

互联网 17-2-27

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");

<?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      }     }

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>aaa@263.net</Email>      <Message>ok</Message>      <STime>2004-07-12T00:00:00.0000000+08:00</STime>    </User>    <User>      <Name>shaoazhd</Name>      <City>beijing</City>      <Email>sss@22.net</Email>      <Message>afsa</Message>      <STime>2004-7-12 15:07:39</STime>    </User>    <User>      <Name>Guset</Name>      <City>上海</City>      <Email>sfaf@22.net</Email>    </User>    <User>      <Name>Guset</Name>      <City>上海</City>      <Email>ss@22.net</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            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="ss@22.net";              xe1.AppendChild(xesub3);                 root.AppendChild(xe1);//添加到<dbGuest>节点中              xmlDoc.Save(Server.MapPath(".\\db\\dbGuest.xml"));              Bind();          }      }  }

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