请问在asp.net中如何实现提取某一网页中局部信息的功能.我现在只能提取页面全部代码

static string GetPageSource(string strURL)
{
Uri uri =new Uri(strURL);
HttpWebRequest Req = (HttpWebRequest)WebRequest.Create(uri);
HttpWebResponse Res = (HttpWebResponse)Req.GetResponse();
Req.Method = "Get";
Req.KeepAlive = false;
StreamReader str = new StreamReader(Res.GetResponseStream(),System.Text.Encoding.GetEncoding("GB2312"));
return str.ReadToEnd();
}

[此贴子已经被作者于2006-8-4 16:46:17编辑过]

webresponse res=re.getresponse
webheadercollection rec=res.headers;
for(int i=0;i<rec.count;i++)
{
console.writeline(rec.getkeys(i)+rec[i])

}

还是不行,我是个菜鸟来的,请问可以给我一个例子吗?只要想提取一个页面的文章,谢谢!!!