网页采集c#

        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 =
                "<a href='http://list.mp3.baidu.com/topso/" +
                "mp3topsong.html?id=1#top2' target='_blank'>" +
                "http://list.mp3.baidu.com/...</a>";   
  
            //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 trin 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");   
               
903f
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;   
        }