xml_操作

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.IO;
using System.Xml;

namespace XmlDom
{
 /// <summary>
 /// WebForm1 的摘要说明。
 /// </summary>
 public class WebForm1 : System.Web.UI.Page
 {
  protected System.Web.UI.WebControls.TextBox TextBox1;
  protected System.Web.UI.WebControls.TextBox TextBox2;
  protected System.Web.UI.WebControls.TextBox TextBox3;
  protected System.Web.UI.WebControls.Button Button1;
  protected System.Web.UI.WebControls.DataGrid DataGrid1;
 
  private void Page_Load(object sender, System.EventArgs e)
  {
   // 在此处放置用户代码以初始化页面
   ReadXml();
  }

  private void ReadXml()
  {
   string url = Server.MapPath("User.xml");//获得当前文件夹下的XML文件
   StreamReader sRead = new StreamReader(url,System.Text.Encoding.GetEncoding("GB2312"));//以一种特定的编码从字节流读取字符,必须要转化成GB2312读取才不能出乱码
   XmlDataDocument datadoc = new XmlDataDocument();//操作XML文档
   datadoc.DataSet.ReadXml(sRead);//将读取的字节流存到DataSet里面去
   this.DataGrid1.DataSource = datadoc.DataSet.Tables[0].DefaultView;
   DataGrid1.DataKeyField="username";//以username建立索引
   this.DataGrid1.DataBind();
   datadoc = null;//清空对XML数据的操作
   sRead.Close();//关闭字节流的读取

  }

  #region Web 窗体设计器生成的代码
  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.DataGrid1.CancelCommand += new System.Web.UI.WebControls.DataGridCommandEventHandler(this.DataGrid1_CancelCommand);
   this.DataGrid1.EditCommand += new System.Web.UI.WebControls.DataGridCommandEventHandler(this.DataGrid1_EditCommand);
   this.DataGrid1.UpdateCommand += new System.Web.UI.WebControls.DataGridCommandEventHandler(this.DataGrid1_UpdateCommand);
   this.DataGrid1.DeleteCommand += new System.Web.UI.WebControls.DataGridCommandEventHandler(this.DataGrid1_DeleteCommand);
   this.Button1.Click += new System.EventHandler(this.Button1_Click);
   this.Load += new System.EventHandler(this.Page_Load);

  }
  #endregion

  private void DataGrid1_DeleteCommand(object source, System.Web.UI.WebControls.DataGridCommandEventArgs e)
  {
    string url = Server.MapPath("user.xml");
    string str_username=DataGrid1.DataKeys[e.Item.ItemIndex].ToString();
    XmlDocument xmlDoc=new XmlDocument();
    xmlDoc.Load(url); //加载XML文件
    XmlNode root=xmlDoc.SelectSingleNode("UserInfo");//查找UserInfo节点
    XmlNodeList xnl=root.ChildNodes; //获取UserInfo下面所以子节点
    for(int i=0;i<xnl.Count;i++)
    {
     XmlNodeList xnl11=xnl.Item(i).SelectNodes("username");//查找username下面节点集合
     XmlElement xe=(XmlElement)xnl11.Item(0); //username节点下面的元素
     if(xe.InnerText==str_username) //获取节点以及所有子集的串联值
     {

      root.RemoveChild(xe.ParentNode);//移除指顶节点
      //     xe.ParentNode.RemoveChild(xe);
      //     xnl.Item(i).RemoveChild(xe);
      //     if(i<xnl.Count)i=i-1;
     }
    }
    xmlDoc.Save(url);
    ReadXml();

  }

  private void Button1_Click(object sender, System.EventArgs e)
  {
   string url = Server.MapPath("user.xml");
   string str_username = this.TextBox1.Text.ToString();
   string str_password = this.TextBox2.Text.ToString();
   string str_study = this.TextBox3.Text.ToString();
   try
   {
    XmlDocument xmlDoc=new XmlDocument();
    xmlDoc.Load(url); //加载XML文档
    XmlNode root=xmlDoc.SelectSingleNode("UserInfo");//查找第一个匹配的XmlNode
    XmlElement xe1=xmlDoc.CreateElement("datarow");//创建第一个节点的第一个元素

    XmlElement xesub1=xmlDoc.CreateElement("username"); //创建第一个节点的第一个元素里的属性
    xesub1.InnerText=str_username;//设置文本节点
    xe1.AppendChild(xesub1);//将指定节点添加到该节点的子节点列表的末尾
    XmlElement xesub2=xmlDoc.CreateElement("password");
    xesub2.InnerText=str_password;
    xe1.AppendChild(xesub2);
    XmlElement xesub3=xmlDoc.CreateElement("study");
    xesub3.InnerText=str_study;
    xe1.AppendChild(xesub3);

    root.AppendChild(xe1);
    xmlDoc.Save (url);//保存XML文件

    ReadXml();
   }
   catch (Exception ex)
   {
    Response.Write(ex.ToString());
   }

  }

  private void DataGrid1_EditCommand(object source, System.Web.UI.WebControls.DataGridCommandEventArgs e)
  {
   this.DataGrid1.EditItemIndex=e.Item.ItemIndex;
   ReadXml();
  }

  private void DataGrid1_CancelCommand(object source, System.Web.UI.WebControls.DataGridCommandEventArgs e)
  {
   this.DataGrid1.EditItemIndex=-1;
   ReadXml();
  }

  private void DataGrid1_UpdateCommand(object source, System.Web.UI.WebControls.DataGridCommandEventArgs e)
  {
   string url = Server.MapPath("user.xml");
   string str_username=DataGrid1.DataKeys[e.Item.ItemIndex].ToString();

   TextBox txt_username = (TextBox)(e.Item.Cells[2].Controls[0]);
   TextBox txt_password = (TextBox)(e.Item.Cells[3].Controls[0]);
   TextBox drp_study=(TextBox)(e.Item.Cells[4].Controls[0]);

   XmlDocument xmlDoc=new XmlDocument();
   xmlDoc.Load(url); //加载XML文件
   XmlNode root=xmlDoc.SelectSingleNode("UserInfo");//查找UserInfo节点
   XmlNodeList xnl=root.ChildNodes; //获取UserInfo下面所以子节点
   for(int i=0;i<xnl.Count;i++)
   {
    XmlNodeList xnl11=xnl.Item(i).SelectNodes("username");//查找username下面节点集合
    XmlElement xe=(XmlElement)xnl11.Item(0); //username节点下面的元素
    if(xe.InnerText==str_username) //获取节点以及所有子集的串联值
    {
     xe.InnerText=txt_username.Text;
     xe.ParentNode.ChildNodes.Item(1).InnerText=txt_password.Text;
     xe.ParentNode.ChildNodes.Item(2).InnerText=drp_study.Text;
    }

   }
   xmlDoc.Save(url);
   this.DataGrid1.EditItemIndex = -1;
   ReadXml();

  }
 }
}