利用HttpWebRequest自动抓取

1、利用httpwatch找到网站入口及参数：（详情略，请百度httpwatch的使用方法）

2、利用httpwebRequest将51拉查看密码Post到网站入口,登陆成功后再进入你想要进入的页面抓取页面 

<!--<br /><br />Code highlighting produced by Actipro CodeHighlighter (freeware)<br />http://www.CodeHighlighter.com/<br /><br />-->          ///   <summary>
         ///  某日或者叫时间段，51la里组员ID里——搜索引擎内——的数据。
         ///   </summary>
         ///   <param name="strStaticId"></param>
         ///   <param name="LookPass"></param>
         ///   <param name="strBeginDate"></param>
         ///   <param name="strEndDate"></param>
         ///   <returns></returns>
         public   string  FiveLaSeo( string  strStaticId,  string  LookPass, string  strBeginDate, string  strEndDate)
        {
            CookieContainer Cc  =   new  CookieContainer();

            ASCIIEncoding encoding  =   new  ASCIIEncoding();
             string  postData  =   " id= "   +  strStaticId;
            postData  +=  ( " &lookpass= "   +  LookPass);
            postData  +=   " &t=chalogin " ;

             // 将提交的字符串数据转换成字节数组
             byte [] data  =  encoding.GetBytes(postData);

             //  设置提交的相关参数   
            HttpWebRequest myRequest  =  (HttpWebRequest)WebRequest.Create( " http://www.51.la/report/0_help.asp " );
            myRequest.Method  =   " POST " ;
            myRequest.ContentType  =   " application/x-www-form-urlencoded " ;
            myRequest.ContentLength  =  data.Length;
             // cookie的容器一定要加
            myRequest.CookieContainer  =  Cc;

             //  提交请求数据  
            Stream newStream  =  myRequest.GetRequestStream();            
            newStream.Write(data,  0 , data.Length);
            newStream.Close();

             //  接收返回的页面  
            HttpWebResponse myResponse  =  (HttpWebResponse)myRequest.GetResponse();
            StreamReader reader  =   new  StreamReader(myResponse.GetResponseStream(), Encoding.Default);
             string  content  =  reader.ReadToEnd();

             // 进去后打开特定页面的参数设置
            myRequest  =  (HttpWebRequest)WebRequest.Create( " http://www.51.la/report/3_SE.asp?id= "   +  strStaticId  +   " &d1= "   +  strBeginDate  +   " &d2= "   +  strEndDate);
            myRequest.Method  =   " GET " ;
            myRequest.KeepAlive  =   false ;
            myRequest.CookieContainer  =  Cc;

             // 接收返回的特定页面
            myResponse  =  (HttpWebResponse)myRequest.GetResponse();
            newStream  =  myResponse.GetResponseStream();
            reader  =   new  StreamReader(myResponse.GetResponseStream(),Encoding.Default);
            content  =  reader.ReadToEnd();
             return  content;
        }

 

3、将抓取的页面进行正则表达式匹配，取出自己所需要的数据（这里我需要搜索引擎流量） 

<!--<br /><br />Code highlighting produced by Actipro CodeHighlighter (freeware)<br />http://www.CodeHighlighter.com/<br /><br />-->          ///   <summary>
         ///  返回51拉中:搜索引擎的访问量IP-*?表示匹配最少的重复项目
         ///   </summary>
         ///   <param name="strStaticId"></param>
         ///   <param name="LookPass"></param>
         ///   <param name="strBeginDate"></param>
         ///   <param name="strEndDate"></param>
         ///   <returns></returns>
         public   string  FivelaSeoPv( string  strStaticId,  string  LookPass, string  strBeginDate, string  strEndDate)
        {
            Tool.FiveLa fl  =   new  FiveLa();
             string  html = fl.FiveLaSeo(strStaticId, LookPass, strBeginDate, strEndDate);
             string  pattern  =   @" 来自搜索引擎的访问量 \( [\s\S]*? IP \) 占总访问量 " ;
             // string pattern = @"占总访问量";
             string  number  =  Regex.Match(html, pattern, RegexOptions.IgnoreCase).Value;
            number  =  number.Replace( " 来自搜索引擎的访问量 ( " ,  "" ).Replace( "  IP ) " ,  "" ).Replace( " 占总访问量 " , "" ).Trim(); ;
             if  (number  ==   "" )
            { number  =   " 0 " ; }
             return  number;
        }