XML操作

读取：
XmlDocument source = new XmlDocument();
   XmlNode objnode;
   int i;
   string title,href;
   //载入新闻列表的XML文件
   source.Load(Server.MapPath("contents.xml"));
   objnode=source.SelectSingleNode("topiclist");
   //生成新闻列表
   Response.Write("<Table border=1>") ;
   Response.Write("<tr>");
   Response.Write("<td>");
   Response.Write("标  题");
   Response.Write("</td>");
   Response.Write("</tr>");
   if(objnode.HasChildNodes)
   {
    for(i=0;i<objnode.ChildNodes.Count;i++)
    {

     Response.Write("<tr>");
     title=objnode.ChildNodes[i].ChildNodes[0].InnerText;
     Response.Write("<td><a href=");
     href=objnode.ChildNodes[i].ChildNodes[1].InnerText;
     Response.Write(href);
     Response.Write(" target=main>");
     Response.Write(title);
     Response.Write("</a>");
     Response.Write("</td>");
     Response.Write("</tr>")  ;
    }
   }
   Response.Write("</table>");

//====================================================================================
写入：
if (File.Exists(Server.MapPath(TextBox1.Text +".xml")))
    Response.Write("文件名已经存在，请重新选文件名!");
   else
   {
    //首先将数据插入新闻列表中
    XmlNode CurrNode;
    XmlDocument xmldoc = new XmlDocument();
    //加载索引文件
    xmldoc.Load(Server.MapPath("contents.xml"));
    string insstr;
    //生成新闻索引
    insstr="<topic><title>" +TextBox2.Text + "</title><href>main.aspx?name=" +TextBox1.Text + "</href></topic>";
    XmlDocumentFragment docFrag =xmldoc.CreateDocumentFragment();
    docFrag.InnerXml = insstr;
    CurrNode=xmldoc.DocumentElement;
    //插入新闻索引队列中
    CurrNode.InsertAfter(docFrag, CurrNode.LastChild);
    //保存索引文件
    xmldoc.Save (Server.MapPath("contents.xml"));

    //把TextBox5中的文件换成符合xml格式的内容
    string xmlfile;
    xmlfile=TextBox5.Text;
    xmlfile=xmlfile.Replace("<","+lt; ");
    xmlfile=xmlfile.Replace(">","+gt; ") ;
    xmlfile=xmlfile.Replace("//","+apos;") ;
    xmlfile=xmlfile.Replace ("\r\n","</paragraph><paragraph>");
    //把数据写入新建的xml文件中去;
    XmlDocument doc;
    doc=new XmlDocument() ;
    insstr="<?xml version='1.0' encoding='GB2312'?><document><title>" ;
    insstr +=TextBox2.Text  +"</title><abstract>" + TextBox4.Text ;
    insstr +="</abstract><author>" +TextBox3.Text +"</author><content><paragraph>";
    insstr +=xmlfile +"</paragraph></content></document>";
    doc.LoadXml(insstr) ;
    doc.Save (Server.MapPath(TextBox1.Text +".xml")) ;
    
   }
//===========================================================================================
CONTENTS.XML文件：
<?xml version="1.0" encoding="GB2312"?>
<topiclist type="Dreamsite News">
  <topic>
    <title>欢迎进入星球新闻网!</title>
    <href>main.aspx?name=hello</href>
  </topic>
  <topic>
    <title>测试新闻</title>
    <href>main.aspx?name=test</href>
  </topic>
  <topic>
    <title> 第一条新闻</title>
    <href>main.aspx?name=first</href>
  </topic>
  <topic>
    <title> 第二条新闻</title>
    <href>main.aspx?name=second</href>
  </topic>
  <topic>
    <title> 第三条新闻</title>
    <href>main.aspx?name=third</href>
  </topic>
  <topic>
    <title>第四条新闻</title>
    <href>main.aspx?name=fourth</href>
  </topic>
  <topic>
    <title>第五条新闻</title>
    <href>main.aspx?name=fifth</href>
  </topic>
  <topic>
    <title>第八条新闻</title>
    <href>main.aspx?name=eighth</href>
  </topic>
  <topic>
    <title>第八条新闻</title>
    <href>main.aspx?name=eighth</href>
  </topic>
  <topic>
    <title>第八条新闻</title>
    <href>main.aspx?name=eighth</href>
  </topic>
  <topic>
    <title>最后一条新闻</title>
    <href>main.aspx?name=last</href>
  </topic>
  <topic>
    <title>大风天气</title>
    <href>main.aspx?name=first</href>
  </topic>
  <topic>
    <title>大风</title>
    <href>main.aspx?name=first</href>
  </topic>
  <topic>
    <title>sss</title>
    <href>main.aspx?name=my.xml</href>
  </topic>
  <topic>
    <title>sss</title>
    <href>main.aspx?name=my.xml</href>
  </topic>
  <topic>
    <title>dfsf</title>
    <href>main.aspx?name=aa</href>
  </topic>
  <topic>
    <title>a</title>
    <href>main.aspx?name=a</href>
  </topic>
  <topic>
    <title>a</title>
    <href>main.aspx?name=a</href>
  </topic>
  <topic>
    <title>a</title>
    <href>main.aspx?name=a</href>
  </topic>
  <topic>
    <title>a</title>
    <href>main.aspx?name=a</href>
  </topic>
  <topic>
    <title>大风</title>
    <href>main.aspx?name=first</href>
  </topic>
  <topic>
    <title>太累</title>
    <href>main.aspx?name=mynews</href>
  </topic>
</topiclist>

//=========================================================================================
private void Page_Load(object sender, System.EventArgs e)
  {
   ArrayList ar =new ArrayList();
   //获取当前目录的路径
   string dr =Server.MapPath("./");
   //获取当前目录下的所有XML文件
   string[] fils =Directory.GetFiles(dr,"*.xml");
   string Filename;
   int pos ;
   pos  = dr.Length+1;
   //显示当前目录下的新闻文件
   for(int i=0;i<fils.Length;i++)
   {
    Filename=Path.GetFileName(fils[i]);
    if( Filename.ToLower()!="contents.xml" )
     ar.Add(Filename);
   }
   dg.DataSource=ar;
   dg.DataBind();
  }

private void submit_Click(object sender, System.EventArgs e)
  {
   if(Page.IsValid)
   {
    XmlDocument Xdoc = new XmlDocument();
    XmlNode objnode;
    string path,xmlfile;
    path=fname.Text;
    Xdoc.Load(path);
    //替换节点内容
    objnode=Xdoc.SelectSingleNode("document");
    objnode.ChildNodes[0].InnerText=title.Text;
    objnode.ChildNodes[2].InnerText=author.Text;
    objnode.ChildNodes[1].InnerText=abs.Text;
    xmlfile=cont.Text;
    //转换新闻内容格式
    xmlfile=xmlfile.Replace("<","&lt; ");
    xmlfile=xmlfile.Replace(">","&gt; ") ;
    xmlfile=xmlfile.Replace ("\r\n","</paragraph><paragraph>");
    xmlfile="<paragraph>" + xmlfile;
    xmlfile=xmlfile + "</paragraph>";
    objnode.ChildNodes[3].InnerText=xmlfile;
    Xdoc.Save(path);
    dis.Visible=false;
    Response.Write("修改成功!");
   }
  }

  private void dg_ItemCommand(object source, System.Web.UI.WebControls.DataGridCommandEventArgs e)
  {
   if( e.CommandName=="update")
   {
    string href,path,content;
    XmlDocument Xdoc = new XmlDocument();
    XmlNode objnode;
    href=e.Item.Cells[1].Text;
    path=Server.MapPath(href);
    Xdoc.Load(path);
    try
    {
     //存储文件名
     fname.Text=path;
     //获取各个节点的值
     objnode=Xdoc.SelectSingleNode("document");
     title.Text=objnode.ChildNodes[0].InnerText;
     author.Text=objnode.ChildNodes[2].InnerText;
     abs.Text=objnode.ChildNodes[1].InnerText;
     content=objnode.ChildNodes[3].InnerText;
     //替换XML格式
     content=content.Replace("&lt; ","<");
     content=content.Replace("&gt; ",">");
     content=content.Replace("</paragraph><paragraph>","\r\n");
     content=content.Replace("</paragraph>","");
     content=content.Replace("<paragraph>","");
     cont.Text=content;
     dis.Visible=true;
    }
    catch( Exception ee)
    {
     Response.Write(ee.ToString());
    }
   }
  }

//=========================================================================================
Hello.xml文件：
<?xml version="1.0" encoding="GB2312"?>
<document>
  <title>欢迎进入星球新闻网!</title>
  <abstract>Welcome</abstract>
  <author>shaozhd111</author>
  <content>&lt;paragraph&gt;首先欢迎您进入星球新闻网!&lt;/paragraph&gt;&lt;paragraph&gt;再次欢迎您进入星球新闻网!&lt;/paragraph&gt;</content>
</document>