HtmlAgilityPack解析网页HTML

HtmlAgilityPack是一个开源的解析HTML元素的类库，最大的特点是可以通过XPath来解析HMTL，如果您以前用C#操作过XML，那么使用起HtmlAgilityPack也会得心应手。
开源地址如下：
http://htmlagilitypack.codeplex.com/
可通过 nuget搜索 HtmlAgilityPack  使用。
另外建议结合ScrapySharp 一起使用，效果更好
ScrapySharp 主要是实现 类似jquery一样的选择器（cssselect），可以直接解析出需要的 htmlnode
当然 ScrapySharp 也可以通过 nuget下载安装到项目

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using HtmlAgilityPack;
using System.Text;

namespace HtmlAgilityDemo
{
    public partial class WebForm1 : System.Web.UI.Page
    {
        protected void Page_Load（object sender EventArgs e）
        {

        }

        protected void btnHtml_Click（object sender EventArgs e）
        {
            if （tbUrl.Text.Length > 0）
            {
                HtmlWeb htmlWeb = new HtmlWeb（）;
                HtmlDocument htmlDoc = htmlWeb.Load（this.tbUrl.Text）;
                HtmlNode htmlNode = htmlDoc.DocumentNode.SelectSingleNode（“//input[@id=‘__VIEWSTATE‘]“）;
                string viewStateValue = htmlNode.Attributes[“value“].

 属性            大小     日期    时间   名称
----------- ---------  ---------- -----  ----

     文件       5632  2013-09-15 18:16  HtmlAgilityDemo\HtmlAgilityDemo\bin\HtmlAgilityDemo.dll

     文件      13824  2013-09-15 18:16  HtmlAgilityDemo\HtmlAgilityDemo\bin\HtmlAgilityDemo.pdb

    .......    134656  2012-08-06 21:31  HtmlAgilityDemo\HtmlAgilityDemo\bin\HtmlAgilityPack.dll

     文件     271872  2012-08-06 21:31  HtmlAgilityDemo\HtmlAgilityDemo\bin\HtmlAgilityPack.pdb

     文件     122991  2012-08-06 21:31  HtmlAgilityDemo\HtmlAgilityDemo\bin\HtmlAgilityPack.xml

     文件     134656  2012-08-06 21:31  HtmlAgilityDemo\HtmlAgilityDemo\Dll\HtmlAgilityPack.dll

     文件     271872  2012-08-06 21:31  HtmlAgilityDemo\HtmlAgilityDemo\Dll\HtmlAgilityPack.pdb

     文件     122991  2012-08-06 21:31  HtmlAgilityDemo\HtmlAgilityDemo\Dll\HtmlAgilityPack.xml

     文件       5631  2013-09-15 13:56  HtmlAgilityDemo\HtmlAgilityDemo\HtmlAgilityDemo.csproj

     文件       1172  2013-09-15 14:58  HtmlAgilityDemo\HtmlAgilityDemo\HtmlAgilityDemo.csproj.user

     文件       8159  2013-09-15 13:55  HtmlAgilityDemo\HtmlAgilityDemo\obj\Debug\DesignTimeResolveAssemblyReferencesInput.cache

     文件        571  2013-09-15 16:33  HtmlAgilityDemo\HtmlAgilityDemo\obj\Debug\HtmlAgilityDemo.csproj.FileListAbsolute.txt

     文件       8059  2013-09-15 14:58  HtmlAgilityDemo\HtmlAgilityDemo\obj\Debug\HtmlAgilityDemo.csprojResolveAssemblyReference.cache

     文件       5632  2013-09-15 18:16  HtmlAgilityDemo\HtmlAgilityDemo\obj\Debug\HtmlAgilityDemo.dll

     文件      13824  2013-09-15 18:16  HtmlAgilityDemo\HtmlAgilityDemo\obj\Debug\HtmlAgilityDemo.pdb

     文件          0  2013-09-15 13:55  HtmlAgilityDemo\HtmlAgilityDemo\obj\Debug\TemporaryGeneratedFile_036C0B5B-1481-4323-8D20-8F5ADCB23D92.cs

     文件          0  2013-09-15 13:55  HtmlAgilityDemo\HtmlAgilityDemo\obj\Debug\TemporaryGeneratedFile_5937a670-0e60-4077-877b-f7221da3dda1.cs

     文件          0  2013-09-15 13:55  HtmlAgilityDemo\HtmlAgilityDemo\obj\Debug\TemporaryGeneratedFile_E7A71F73-0F8D-4B9B-B56E-8E70B10BC5D3.cs

     文件       1350  2013-09-15 13:27  HtmlAgilityDemo\HtmlAgilityDemo\Properties\AssemblyInfo.cs

     文件        611  2013-09-15 13:55  HtmlAgilityDemo\HtmlAgilityDemo\Web.config

     文件       1245  2013-09-15 13:27  HtmlAgilityDemo\HtmlAgilityDemo\Web.Debug.config

     文件       1306  2013-09-15 13:27  HtmlAgilityDemo\HtmlAgilityDemo\Web.Release.config

     文件       1039  2013-09-15 18:18  HtmlAgilityDemo\HtmlAgilityDemo\WebForm1.aspx

     文件       1354  2013-09-15 18:14  HtmlAgilityDemo\HtmlAgilityDemo\WebForm1.aspx.cs

     文件       2549  2013-09-15 18:13  HtmlAgilityDemo\HtmlAgilityDemo\WebForm1.aspx.designer.cs

     文件        935  2013-09-15 13:27  HtmlAgilityDemo\HtmlAgilityDemo.sln

    ..A..H.     23552  2013-09-15 19:11  HtmlAgilityDemo\HtmlAgilityDemo.v11.suo

     目录          0  2013-09-15 13:27  HtmlAgilityDemo\HtmlAgilityDemo\obj\Debug\TempPE

     目录          0  2013-09-15 18:16  HtmlAgilityDemo\HtmlAgilityDemo\obj\Debug

     目录          0  2013-09-15 14:58  HtmlAgilityDemo\HtmlAgilityDemo\bin

............此处省略8个文件信息