使用HtmlAgilityPack XPath 表达式抓取博客园数据的实现代码

Web 前端代码


代码如下:

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<table cellpadding="1" cellspacing="1" bgcolor="#f1f1f1" style="text-align: center">
<asp:Repeater ID="Repeater1" runat="server">
<HeaderTemplate>
<tr>
<td>
标题
</td>
<td>
发布作者
</td>
<td>
发布时间
</td>
</tr>
</HeaderTemplate>
<ItemTemplate>
<tr bgcolor="#ffffff">
<td align="left">
<a href='<%#Eval("url") %>' target="_blank">
<%#Eval("title") %>
</a>
</td>
<td>
<a href='<%#Eval("authorUrl") %>' target="_blank">
<%#Eval("author") %>
</a>
</td>
<td>
<%#Eval("updatetime") %>
</td>
</tr>
</ItemTemplate>
</asp:Repeater>
</table>
</div>
</form>
</body>
</html>

cs 后台代码：


代码如下:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using S1;
using System.Net;
using System.IO;
using System.Text;
using HtmlAgilityPack;
public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
string page = string.Empty;
if (!IsPostBack)
{
WebClient wc = new WebClient();
string address = "http://www.cnblogs.com";
if (!string.IsNullOrEmpty(Request.QueryString["p"]))
{
address += "/" + Request.QueryString["p"];//分页，p=p2,p=p3
}
Stream stream = wc.OpenRead(address);
StreamReader sr = new StreamReader(stream, Encoding.UTF8);
string html = sr.ReadToEnd();
//实例化HtmlAgilityPack.HtmlDocument对象
HtmlDocument doc = new HtmlDocument();
//载入HTML
doc.LoadHtml(html);
//根据HTML节点NODE的ID获取节点
HtmlNode navNode = doc.GetElementbyId("post_list");
//div[2]表示文章链接a位于post_list里面第3个div节点中
HtmlNodeCollection list = navNode.SelectNodes("//div[2]/h3/a"); //根据XPATH来索引节点
Cnblogs cnblogs = null;
IList<Cnblogs> cnlist = new List<Cnblogs>();
foreach (HtmlNode node in list)
{
cnblogs = new Cnblogs();
//获取文章链接地址
cnblogs.url = node.Attributes["href"].Value.ToString();
//获取文章标题
cnblogs.title = node.InnerText;
cnlist.Add(cnblogs);
}
HtmlNodeCollection list1 = navNode.SelectNodes("//div[2]/div/a");
for (int i = 0; i < cnlist.Count; i++)
{
cnlist[i].author = list1[i].InnerText;
cnlist[i].authorUrl = list1[i].Attributes["href"].Value.ToString();
cnlist[i].updatetime = list1[i].NextSibling.InnerText.Replace("发布于", "").Trim();
}
this.Repeater1.DataSource = cnlist;
this.Repeater1.DataBind();
}
}
public class Cnblogs
{
public string title { get; set; }
public string url { get; set; }
public string author { get; set; }
public string authorUrl { get; set; }
public string updatetime { get; set; }
}
}