解讀XML 增、刪、改和查示例

2024-09-05 20:54:40

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1.已知有一個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>節點中插入一個<book>節點：

XmlDocument xmlDoc=new XmlDocument();
xmlDoc.Load("bookstore.xml");
XmlNode root=xmlDoc.SelectSingleNode("bookstore");//查找<bookstore>
XmlElement xe1=xmlDoc.CreateElement("book");//創建一個<book>節點
xe1.SetAttribute("genre","李贊紅");//設置該節點genre屬性
xe1.SetAttribute("ISBN","2-3631-4");//設置該節點ISBN屬性

XmlElement xesub1=xmlDoc.CreateElement("title");
xesub1.InnerText="CS從入門到精通";//設置文本節點
xe1.AppendChild(xesub1);//添加到<book>節點中
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>節點中
xmlDoc.Save("bookstore.xml");

//================
結果為：

<?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="李贊紅" ISBN="2-3631-4">
<title>CS從入門到精通</title>
<author>候捷</author>
<price>58.3</price>
</book>
</bookstore>

2、修改節點：將genre屬性值為“李贊紅“的節點的genre值改為“update李贊紅”，將該節點的子節點<author>的文本修改為“亞勝”。

XmlNodeList nodeList=xmlDoc.SelectSingleNode("bookstore").ChildNodes;//獲取bookstore節點的所有子節點
foreach(XmlNode xn in nodeList)//遍歷所有子節點
{
XmlElement xe=(XmlElement)xn;//將子節點類型轉換為XmlElement類型
if(xe.GetAttribute("genre")=="李贊紅")//如果genre屬性值為“李贊紅”
{
xe.SetAttribute("genre","update李贊紅");//則修改該屬性為“update李贊紅”

XmlNodeList nls=xe.ChildNodes;//繼續獲取xe子節點的所有子節點
foreach(XmlNode xn1 in nls)//遍歷
{
XmlElement xe2=(XmlElement)xn1;//轉換類型
if(xe2.Name=="author")//如果找到
{
xe2.InnerText="亞勝";//則修改
break;//找到退出來就可以了
}
}
break;
}
}

xmlDoc.Save("bookstore.xml");//保存。

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

最后結果為：

<?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李贊紅" ISBN="2-3631-4">
<title>CS從入門到精通</title>
<author>亞勝</author>
<price>58.3</price>
</book>
</bookstore>

3、刪除 <book genre="fantasy" ISBN="2-3631-4">節點的genre屬性，刪除 <book genre="update李贊紅" ISBN="2-3631-4">節點。

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

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

if(xe.GetAttribute("genre")=="fantasy")
{
xe.RemoveAttribute("genre");//刪除genre屬性
}
else if(xe.GetAttribute("genre")=="update李贊紅")
{
xe.RemoveAll();//刪除該節點的全部內容
}
}
xmlDoc.Save("bookstore.xml");

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

最后結果為：

<?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、顯示所有數據。

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

XmlNodeList xnl=xn.ChildNodes;

foreach(XmlNode xnf in xnl)
{
XmlElement xe=(XmlElement)xnf;
Console.WriteLine(xe.GetAttribute("genre"));//顯示屬性值
Console.WriteLine(xe.GetAttribute("ISBN"));

XmlNodeList xnf1=xe.ChildNodes;
foreach(XmlNode xn2 in xnf1)
{
Console.WriteLine(xn2.InnerText);//顯示子節點點文本
}
}

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

2前臺代碼：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="宋體">
<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">新郵件地址：</asp:Label>
<asp:Label id="Label2" style="Z-INDEX: 107; LEFT: 333px; POSITION: absolute; TOP: 274px" runat="server" Width="83px" Height="21px">郵件地址：</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="刪除"></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="查詢"></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 的摘要說明。
/// </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)
{
// 在此處放置用戶代碼以初始化頁面
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：該調用是 ASP.NET Web 窗體設計器所必需的。
//
InitializeComponent();
base.OnInit(e);
}

/**//// <summary>
/// 設計器支持所需的方法 - 不要使用代碼編輯器修改
/// 此方法的內容。
/// </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;//獲取dbGuest節點的所有子節點
foreach(XmlNode xn in nodeList)//遍歷所有子節點
{
XmlElement xe=(XmlElement)xn;//將子節點類型轉換為XmlElement類型

XmlNodeList node = xe.GetElementsByTagName("Name");
if(node.Count>0)
{

if(node[0].InnerText==ddlName.SelectedItem.Text)
{
XmlNodeList nls=xe.ChildNodes;//繼續獲取xe子節點的所有子節點
foreach(XmlNode xn1 in nls)//遍歷
{
XmlElement xe2=(XmlElement)xn1;//轉換類型
if(xe2.Name=="Email")//如果找到
{
xe2.InnerText=tbNewMail.Text;//則修改
break;//找到退出來就可以了
}
}
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();//刪除該節點的全部內容
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");//創建一個<User>節點
XmlElement xesub1=xmlDoc.CreateElement("Name");
xesub1.InnerText="Guset";//設置文本節點
xe1.AppendChild(xesub1);//添加到<User>節點中
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>節點中
xmlDoc.Save(Server.MapPath(".//db//dbGuest.xml"));
Bind();
}
}
}
http://www.56wlw.com/skylaugh/archive/2006/12/18/595634.html