XML add, delete, modify and query examples
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
}
}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();
}
}
} 以上就是XML 增、删、改和查示例的内容，更多相关内容请关注PHP中文网（m.sbmmt.com）！
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