C#页面抓取信息

//根据Url地址得到网页的html源码
         private string GetWebContent(string Url)
         {
             string strResult="";
             try
             {
                 HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Url);
　　　　//声明一个HttpWebRequest请求
                 request.Timeout = 30000;
                //设置连接超时时间
                 request.Headers.Set("Pragma", "no-cache");
                 HttpWebResponse response = (HttpWebResponse)request.GetResponse();
                 Stream streamReceive = response.GetResponseStream();
                 Encoding encoding = Encoding.GetEncoding("GB2312");
                 StreamReader streamReader = new StreamReader(streamReceive, encoding);
                 strResult = streamReader.ReadToEnd();
             }
             catch
             {
                 MessageBox.Show("出错");
             }
             return strResult;
         }
为了使用HttpWebRequest和HttpWebResponse，需填名字空间引用
　　using System.Net;

以下是程序具体实现过程：
private void button1_Click(object sender, EventArgs e)
         {
            //要抓取的URL地址
             string Url = "http://list.mp3.baidu.com/topso/mp3topsong.html?id=1#top2";

            //得到指定Url的源码
　　　string strWebContent = GetWebContent(Url);

             richTextBox1.Text = strWebContent;
　　　 //取出和数据有关的那段源码
             int iBodyStart = strWebContent.IndexOf("<body", 0);
             int iStart = strWebContent.IndexOf("歌曲TOP500", iBodyStart);
             int iTableStart = strWebContent.IndexOf("<table", iStart);
             int iTableEnd = strWebContent.IndexOf("</table>", iTableStart);
             string strWeb = strWebContent.Substring(iTableStart, iTableEnd - iTableStart + 8);

            //生成HtmlDocument
　　　       WebBrowser webb = new WebBrowser();
             webb.Navigate("about:blank");
             HtmlDocument htmldoc = webb.Document.OpenNew(true);
             htmldoc.Write(strWeb);
             HtmlElementCollection htmlTR = htmldoc.GetElementsByTagName("TR");
             foreach (HtmlElement tr in htmlTR)
             {
                 string strID = tr.GetElementsByTagName("TD")[0].InnerText;
                 string strName = SplitName(tr.GetElementsByTagName("TD")[1].InnerText, "MusicName");
                 string strSinger = SplitName(tr.GetElementsByTagName("TD")[1].InnerText, "Singer");
                 strID = strID.Replace(".", "");
                //插入DataTable
                 AddLine(strID, strName, strSinger,"0");

                 string strID1 = tr.GetElementsByTagName("TD")[2].InnerText;
                 string strName1 = SplitName(tr.GetElementsByTagName("TD")[3].InnerText, "MusicName");
                 string strSinger1 = SplitName(tr.GetElementsByTagName("TD")[3].InnerText, "Singer");
                //插入DataTable
                 strID1 = strID1.Replace(".", "");
                 AddLine(strID1, strName1, strSinger1,"0");

                 string strID2 = tr.GetElementsByTagName("TD")[4].InnerText;
                 string strName2 = SplitName(tr.GetElementsByTagName("TD")[5].InnerText, "MusicName");
                 string strSinger2 = SplitName(tr.GetElementsByTagName("TD")[5].InnerText, "Singer");
                //插入DataTable
                 strID2 = strID2.Replace(".", "");
                 AddLine(strID2, strName2, strSinger2,"0");

             }
            //插入数据库
             InsertData(dt);
　　　
             dataGridView1.DataSource = dt.DefaultView;
}