asp.net如何抓取其他网站的内容

using System.Net; 
using System.IO; 
using System.Text; 
using System.Text.RegularExpressions; 

WebRequest request = WebRequest.Create("http://目标网址.com/"); 
WebResponse response = request.GetResponse(); 
StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.GetEncoding("gb2312")); 
//reader.ReadToEnd() 表示取得网页的源码 
TextBox1.Text = reader.ReadToEnd(); 

MatchCollection TitleMatchs = Regex.Matches(reader.ReadToEnd(), @"发表评论</a></p></div><div class=""body"">([\s\S]*?)</div><div class=""share"">", RegexOptions.IgnoreCase | RegexOptions.Multiline); 
foreach (Match NextMatch in TitleMatchs) 
{ 
s += "<br>" + NextMatch.Groups.Value; 
TextBox1.Text += "\n" + NextMatch.Groups.Value; 
}