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步步为营VS 2008 + .NET 3.5(14) - XLINQ(LINQ to XML)之针对XML文件的添加、查询、更新和删除


作者:webabcd


介绍
以某一XML文件为例,XLINQ(LINQ to XML)之针对XML文件的添加操作、查询操作、更新操作和删除操作


示例
Sample.xml
<?xml version="1.0" encoding="utf-8"?>
<root>
    <person name="webabcd" age="27" salary="33" />
</root>
 
Sample.aspx
<%@ Page Language="C#" MasterPageFile="~/Site.master" AutoEventWireup="true" CodeFile="Sample.aspx.cs"
        Inherits="LINQ_XLINQ_Sample" Title="针对XML文件的添加、查询、更新和删除" %>

<asp:Content ID="Content1" ContentPlaceHolderID="head" runat="Server">
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="Server">
        <p>
                姓名:<asp:TextBox ID="txtName" runat="server"></asp:TextBox>
                   年龄:<asp:TextBox ID="txtAge" runat="server"></asp:TextBox>
                   薪水:<asp:TextBox ID="txtSalary" runat="server"></asp:TextBox>
                <asp:Button ID="btnAdd" runat="server" Text="添加" OnClick="btnAdd_Click" />
        </p>
        <asp:GridView ID="gvPerson" runat="server" DataKeyNames="name" OnSelectedIndexChanged="gvPerson_SelectedIndexChanged"
                OnRowDeleting="gvPerson_RowDeleting" OnRowCancelingEdit="gvPerson_RowCancelingEdit"
                OnRowEditing="gvPerson_RowEditing" OnRowUpdating="gvPerson_RowUpdating">
                <Columns>
                        <asp:CommandField ShowSelectButton="True" ShowEditButton="True" ShowDeleteButton="True">
                        </asp:CommandField>
                </Columns>
        </asp:GridView>
        <br />
        <asp:DetailsView ID="dvPerson" runat="server" DataKeyNames="name">
        </asp:DetailsView>
</asp:Content>
 

Sample.aspx.cs
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Xml.Linq;

public partial class LINQ_XLINQ_Sample : System.Web.UI.Page
{
        protected void Page_Load(object sender, EventArgs e)
        {
                if (!Page.IsPostBack)
                {
                        BindPerson();
                }
        }

        private void BindPerson()
        {
                // 加载指定的xml文件
                XDocument xml = XDocument.Load(Server.MapPath("Sample.xml"));

                // 使用查询语法获取Person集合
                var persons = from p in xml.Root.Elements("person")
                                            select new
                                            {
                                                    name = p.Attribute("name").Value,
                                                    age = p.Attribute("age").Value,
                                                    salary = p.Attribute("salary").Value
                                            };

                gvPerson.DataSource = persons;
                gvPerson.DataBind();
        }

        protected void btnAdd_Click(object sender, EventArgs e)
        {
                // 加载指定的xml文件
                XDocument xml = XDocument.Load(Server.MapPath("Sample.xml"));

                // 创建需要新增的XElement对象
                XElement person = new XElement(
                        "person",
                        new XAttribute("name", txtName.Text),
                        new XAttribute("age", txtAge.Text),
                        new XAttribute("salary", txtSalary.Text));

                // 添加需要新增的XElement对象
                xml.Root.Add(person);
                
                // 保存xml
                xml.Save(Server.MapPath("Sample.xml"));

                gvPerson.EditIndex = -1;
                BindPerson();
        }

        protected void gvPerson_SelectedIndexChanged(object sender, EventArgs e)
        {
                // 加载指定的xml文件
                XDocument xml = XDocument.Load(Server.MapPath("Sample.xml"));

                // 使用查询语法获取指定的Person集合
                var persons = from p in xml.Root.Elements("person")
                                            where p.Attribute("name").Value == gvPerson.SelectedValue.ToString()
                                            select new
                                            {
                                                    name = p.Attribute("name").Value,
                                                    age = p.Attribute("age").Value,
                                                    salary = p.Attribute("salary").Value
                                            };

                dvPerson.DataSource = persons;
                dvPerson.DataBind();
        }

        protected void gvPerson_RowDeleting(object sender, GridViewDeleteEventArgs e)
        {
                // 加载指定的xml文件
                XDocument xml = XDocument.Load(Server.MapPath("Sample.xml"));

                // 使用查询语法获取指定的Person集合
                var persons = from p in xml.Root.Elements("person")
                                            where p.Attribute("name").Value == gvPerson.DataKeys[e.RowIndex].Value.ToString()
                                            select p;

                // 删除指定的XElement对象
                persons.Remove();

                // 保存xml
                xml.Save(Server.MapPath("Sample.xml"));

                gvPerson.EditIndex = -1;
                BindPerson();
        }

        protected void gvPerson_RowUpdating(object sender, GridViewUpdateEventArgs e)
        {
                // 加载指定的xml文件
                XDocument xml = XDocument.Load(Server.MapPath("Sample.xml"));

                // 使用查询语法获取指定的Person集合
                var persons = from p in xml.Root.Elements("person")
                                            where p.Attribute("name").Value == gvPerson.DataKeys[e.RowIndex].Value.ToString()
                                            select p;

                // 更新指定的XElement对象
                foreach (XElement xe in persons)
                {
                        xe.SetAttributeValue("age", ((TextBox)gvPerson.Rows[e.RowIndex].Cells[2].Controls[0]).Text);
                        xe.SetAttributeValue("salary", ((TextBox)gvPerson.Rows[e.RowIndex].Cells[3].Controls[0]).Text);
                }

                // 保存xml
                xml.Save(Server.MapPath("Sample.xml"));

                gvPerson.EditIndex = -1;
                BindPerson();
        }

        protected void gvPerson_RowEditing(object sender, GridViewEditEventArgs e)
        {
                gvPerson.EditIndex = e.NewEditIndex;
                BindPerson();
        }

        protected void gvPerson_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e)
        {
                gvPerson.EditIndex = -1;
                BindPerson();
        }
}