ASP.NET 抓取网页源文件

做项目分享的时候要抓取网页里面的图片，及视频，标头。当然要取到这些东西之前，必须把源文件读出来
，拿到源文件之后就用JS正则取图片和视频了（JS正则还不完美，先不贴）
C#抓取网页源文件代码如下：
using System;
using System.Data;
using System.Configuration;
using System.Collections;
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.Net;
using System.IO;
using System.Text;
namespace WebApplication3
{
public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
tb.Text = "";
try
{
WebRequest request = WebRequest.Create("http://v.youku.com/v_show/id_XMTMxMzQyOTQ0.html");
WebResponse response = request.GetResponse();
StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.GetEncoding("UTF-8"));
tb.Text = reader.ReadToEnd();
reader.Close();
reader.Dispose();
response.Close();
}
catch (Exception ex)
{
tb.Text = ex.Message;
}
}
}
}
}