c# 抓取Web网页数据分析

//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; 
}