VB.net 2010 视频教程 VB.net 2010 视频教程 python基础视频教程
SQL Server 2008 视频教程 c#入门经典教程 Visual Basic从门到精通视频教程
当前位置:
首页 > temp > C#教程 >
  • c#实现web信息自动抓取

制作者:剑锋冷月 单位:无忧统计网,www.51stat.net
 

  本文示例源代码或素材下载

  背景

  随着Internet的普及,网络信息正以极高的速度增长,在这么多数据中找到自己需要的信息是一件很繁琐的事情,找到需要的信息后如何获取也是件麻烦的事。这 就需要Internet信息抓取程序来代替人工的操作。

  所谓Internet信息抓取程序,就是程序会按照用户的关键词或关键网站来收集相应的信息,并提供给用户想要的信息格式 。

  信息量的增加会带来信息网站发布人员工作量的剧增,为实现信息发布系统实现信息自

  动发布、减少工作人员工作量、即时跟踪最新信息,就需要自动信息提供 程序,因此Internet信息抓取程序应运而生。

  目标

  实现自定义网站信息分类抓取,存入本地数据库、生成静态页面或其它用户定义的信息结构,并下载与信息相关 的多媒体文件。

  开发

  目标站点结构分析

  本步骤是准确抓取信息个关键。

  首先要选择更新频 率高的页面做为抓取地址,然后分析要抓取内容页面url特点。

  然后分析要抓取信息页面的元素特性,比如标题位置,内容位置 等,得到定位标记点。

  将以上信息 写成自己的配置文件或存到数据库中。

  每个网站都需要分析,写出单独的配置文件,供抓取程序使用。

  信息提取

  根据配置文件取得要抓取页面url,使用HttpWebRequest类获取内容:

//获取http页面函数
        public string Get_Http(string a_strUrl,int timeout)
        {
            string strResult ;        
            try
            {
HttpWebRequest myReq = (HttpWebRequest) HttpWebRequest.Create(a_strUrl) ;
                myReq.Timeout = timeout;
                HttpWebResponse HttpWResp = (HttpWebResponse)myReq.GetResponse();
           
                Stream myStream = HttpWResp.GetResponseStream () ;
                StreamReader sr = new StreamReader (myStream , Encoding.Default);
                StringBuilder strBuilder = new StringBuilder();
                while (-1 != sr.Peek())
                {
                    strBuilder.Append (sr.ReadLine()+" ");
                }
                strResult = strBuilder.ToString ();
            }
            catch(Exception exp)
            {
                strResult = "错误:" + exp.Message ;
            }
            return strResult ;
        }

 

  获取页面内容后,分析页面中连接地址取到要抓取的url:

//处理页面标题和链接
        public string SniffWebUrl( string urlStr,string blockB,string blockE )
        {      
            string urlch1 = "";
            string urlch2 = "";                   
            int end_n1 = 0;
            int end_nums = 0;
            int end_nums1 = 0;
            int end_nums2 = 0;
            int end_nums3     = 0;           
            string reUTStr = "";
            string reTitle = "";
            string ret = "";          
            try
            {
                int pos01 = urlStr.IndexOf( "." );
                int pos02 = urlStr.LastIndexOf( "/" );
                if( pos01 < 0 )
                {
                    return "";
                }
                if( pos02 < 0 )
                {
                    return "";
                }
                int pos03 = urlStr.IndexOf( "/",pos01 );
                if ( pos03 < 0 )
                {
                    urlch1 = urlStr;
                    urlch2 = urlStr;
                }
                else
                {
                    urlch1 = urlStr.Substring( 0,pos03 );
                    urlch2 = urlStr.Substring( 0,pos02 );
                }
                string tmpAllStr = new PublicFun().Get_Http( urlStr ,time1);
                int pos1 = tmpAllStr.IndexOf( blockB );
                int pos2 = tmpAllStr.IndexOf( blockE,pos1 + blockB.Length );
                if ( pos1>0 && pos2>0 && pos2>pos1 )
                {
                    ret = tmpAllStr.Substring( pos1 + blockB.Length,pos2 - pos1 - blockB.Length );
                    ret = ret.Substring( ret.IndexOf( "<" ));
                    while( ret.IndexOf( "<A" ) >= 0 )
                    {
                      &nbs p; ret = ret.Substring( 0,ret.IndexOf( "<A" ) ) + "<a" + ret.Substring( ret.IndexOf( "<A" ) + 2 );
                    }
                    while( ret.IndexOf( "</A" ) >=0 )
                    {
                      &nbs p; ret = ret.Substring( 0,ret.IndexOf( "</A" ) ) + "</a" + ret.Substring( ret.IndexOf( "</A" ) + 3 );
                    }
                    while( ret.IndexOf( "Href=" ) >=0 )
                    {
                      &nbs p; ret = ret.Substring( 0,ret.IndexOf( "Href=" )) + "href=" + ret.Substring( ret.IndexOf( "Href=" ) + 5 );
                    }
                    while( ret.IndexOf( "HREF=" ) >=0 )
                    {
                      &nbs p; ret = ret.Substring( 0,ret.IndexOf( "HREF=" )) + "href=" + ret.Substring( ret.IndexOf( "HREF=" ) + 5 );
                    }
                    while( ret.IndexOf( "href='" ) >=0 )
                    {
                      &nbs p; ret = ret.Substring( 0,ret.IndexOf( "href='" )) + "href="" + ret.Substring( ret.IndexOf( "href='" ) + 6 );
                    }
                }      
                tmpAllStr = ret;     
                int begin_nums = tmpAllStr.IndexOf( "href=" );
                while ( begin_nums >= 0 )
                {              
                    string tmpStrA = "";
                    string tmpStrB = tmpAllStr.Substring( begin_nums + 5,1 );
                    if ( tmpStrB == """ )
                    {
                      &nbs p; end_n1 = begin_nums + 6;
                      &nb sp; if ( ( end_n1 + 1 ) > tmpAllStr.Length )
                        {
                      &nbs p;     return "";
                    &nbs p;   }
                        tmpStrA = tmpAllStr.Substring( begin_nums+6,1 );
                    }
                    else
                    {
                      &nbs p; end_n1 = begin_nums + 5;
                      &nb sp; tmpStrA = tmpStrB;
                    }
                    if ( tmpStrA == "#" )
                    {
                      &nbs p; tmpAllStr = tmpAllStr.Substring( end_n1 );
                      &nb sp; begin_nums = tmpAllStr.IndexOf( "href=" );
                    }
                    else
                    {                  
                        end_nums1 = tmpAllStr.IndexOf( " ",end_n1 );
                      &nb sp; end_nums2 = tmpAllStr.IndexOf( ">",end_n1 );
                      &nb sp; end_nums3 = tmpAllStr.IndexOf( "</a",end_nums2 );
                      &nb sp; if ( ( end_nums3 >= 0 ) && ( end_nums2 >= 0 ) )
                        {
                      &nbs p;     reTitle = tmpAllStr.Substring( end_nums2 + 1,end_nums3 - end_nums2 - 1 );
                      &nb sp;     if ( end_nums1 > end_nums2 )
                            {
                      &nbs p;         end_nums = end_nums2;
                     & nbsp;      }
                            else
                      & nbsp;     {
                      &nbs p;         if ( end_nums1 < 0 )
                                {
                      &nbs p;             end_nums = end_nums2;
                     & nbsp;          }
                                else
                      & nbsp;         {
                      &nbs p;             end_nums = end_nums1;
                     & nbsp;          }
                            }
                            string str4 = tmpAllStr.Substring( end_nums-1, end_nums - end_nums + 1 );
                      &nb sp;     if ( str4 =="""  || str4 == "'" )
                            {
                      &nbs p;         end_nums = end_nums - 1;
                      &nb sp;     }
                            string sTotalOne = tmpAllStr.Substring( end_n1,end_nums - end_n1 );
                      &nb sp;     if ( sTotalOne.IndexOf( "http://" ) <0 )
                            {
                      &nbs p;         if ( sTotalOne.IndexOf( "/" ) == 0 )
                                {
                      &nbs p;             sTotalOne = urlch1 + sTotalOne;
                     & nbsp;          }
                                else
                      & nbsp;         {                               
                                    int linshiIntNum = 0;
                      &nb sp;             int flags = 0;
                      &nb sp;             string urlChange = urlStr;;
                     &nb sp;              while( sTotalOne.IndexOf( "../" ) >= 0 )
                                    {
                      &nbs p;                 sTotalOne = sTotalOne.Substring( sTotalOne.IndexOf( "../" ) + 3 );
                      &nb sp;                 linshiIntNum = linshiIntNum + 1;
                      &nb sp;                 flags = flags +1;
                      &n bsp;             }
                                    while( ( urlChange.LastIndexOf( "/" ) >= 0 ) && ( linshiIntNum >= 0 ) )
                                    {
                      &nbs p;                 urlChange = urlChange.Substring( 0,urlChange.LastIndexOf( "/" ) );
                      &nb sp;                 linshiIntNum = linshiIntNum - 1;
                      &nb sp;             }
                                    if ( flags == 0 )
                                    {
                      &nbs p;                 sTotalOne = urlch2 + "/" + sTotalOne;
                     & nbsp;              }
                                    else
                      & nbsp;             {
                      &nbs p;                 sTotalOne = urlChange + "/" + sTotalOne;
                     & nbsp;              }
                                }
                            }
                            reUTStr = reUTStr + new PublicFun().RemoveHtmlCode( reTitle ) + sTotalOne;
                     & nbsp;      tmpAllStr = tmpAllStr.Substring( end_nums3 + 4 );
                      &nb sp;     begin_nums = tmpAllStr.IndexOf( "href=" );
                      &nb sp; }
                        else
                      & nbsp; {
                      &nbs p;     begin_nums = - 1;
                      &nb sp; }                   
                    }
                }
                return reUTStr;
            }
            catch( Exception e)
            {
                return "";
            }
        }

 

  得到要抓取内容的url后,处理该页面:

//获取链接内容并分类处理
        public string GetWebContent( string gatherUrl,string subUrl,string subTitle,string b_Content,string e_Content,string b_Filter,string e_Filter,string root )
        {
            string tmpAllStr = "";           
            string dfStrB = "";
            string dfStrE = "";               
            string rePicStr = "";//图片返回路径   
            string reContentStr = "";
            string picHtml = "images"; //本地图片路径
           
            string urlch1 ="";
            string urlch2 ="";
            int pos1 = gatherUrl.IndexOf( "." );
            int pos2 = gatherUrl.LastIndexOf( "/" );
            if( pos1 < 0 )
            {
                return "";
            }
            if( pos2 < 0 )
            {               
                return "";
            }
            int pos3 = gatherUrl.IndexOf( "/",pos1 );
            if ( pos3 < 0 )
            {
                urlch1 = gatherUrl;
                urlch2 = gatherUrl;
            }
            else
            {
                urlch1 = gatherUrl.Substring( 0,pos3 );
                urlch2 = gatherUrl.Substring( 0,pos2 );
            }   
           
            tmpAllStr = new PublicFun().Get_Http( subUrl,time1 );
            //取稿源
            string docFromStr = "";
            if ( dfStrB != "" && dfStrE != "" )
            {
                if ( tmpAllStr != "" )
                {
                    int b_docF = tmpAllStr.IndexOf( dfStrB );
                    if ( b_docF > 0 )
                    {
                      &nbs p; int e_docF = tmpAllStr.IndexOf( dfStrE,b_docF + dfStrB.Length );
                      &nb sp; if ( e_docF > 0 && e_docF > b_docF && e_docF - b_docF < 20 )
                        {
                      &nbs p;     docFromStr = tmpAllStr.Substring( b_docF + dfStrB.Length, e_docF - b_docF - dfStrB.Length );
                      &nb sp; }
                    }
                }
            }
            //取内容
            if ( tmpAllStr != "" )
            {               
                int begin_strnum = tmpAllStr.IndexOf( b_Content );
                if ( begin_strnum < 0 )
                {                  
                    return "";
                }
                int end_strnum = tmpAllStr.IndexOf( e_Content,begin_strnum + b_Content.Length );
                if ( end_strnum < 0 )
                {                  
                    return "";
                }
                string sTotalSubM = "";
                if ( end_strnum > begin_strnum )
                {
                    sTotalSubM = tmpAllStr.Substring ( begin_strnum,end_strnum - begin_strnum );
                }
               
                if ( sTotalSubM == "" )
                {                  
                    return "";
                }               
                //过滤无用信息
                int bfnum = sTotalSubM.IndexOf( b_Filter );
                if ( bfnum > -1 )
                {
                    int efnum = sTotalSubM.IndexOf( e_Filter,bfnum );
                    if ( efnum > -1 )
                    {
                      &nbs p; if ( efnum > bfnum )
                        {
                      &nbs p;     sTotalSubM = sTotalSubM.Substring( 0,bfnum ) + sTotalSubM.Substring( efnum + e_Filter.Length );
                      &nb sp; }
                    }
                }
                //格式化图片标记
               
                while( sTotalSubM.IndexOf( "Src=" ) >= 0 )
                {
                    sTotalSubM = sTotalSubM.Substring( 0,sTotalSubM.IndexOf( "Src=" ) ) + "src=" + sTotalSubM.Substring( sTotalSubM.IndexOf( "Src=" ) + 4 );
                }
                while( sTotalSubM.IndexOf( "SRC=" ) >= 0 )
                {
                    sTotalSubM = sTotalSubM.Substring( 0,sTotalSubM.IndexOf( "SRC=" ) ) + "src=" + sTotalSubM.Substring( sTotalSubM.IndexOf( "SRC=" ) + 4 );
                }
                while( sTotalSubM.IndexOf( "src='" ) >= 0 )
                {
                    sTotalSubM = sTotalSubM.Substring( 0,sTotalSubM.IndexOf( "src='" ) ) + "src="" + sTotalSubM.Substring( sTotalSubM.IndexOf( "src='" ) + 5 );
                }
                //取图片地址
                int end_n12 = 0;
                int end_nums2 = 0;
                int begin_nums2 = sTotalSubM.IndexOf( "src=" );
                while( begin_nums2 >= 0 )
                {
                    String tmpStr = sTotalSubM.Substring( begin_nums2 + 4,1 );
                    if ( tmpStr == """ )
                    {
                      &nbs p; end_n12 = begin_nums2 + 5;
                    }
                    else
                    {
                      &nbs p; end_n12 = begin_nums2 + 4;
                    }
                    int end_nums2a = sTotalSubM.IndexOf( " ",end_n12 );
                    int end_nums2b = sTotalSubM.IndexOf( ">",end_n12 );
                    if ( end_nums2b < 0 )
                    {
                      &nbs p; break;
                    }
                    if ( end_nums2a > end_nums2b )
                    {
                      &nbs p; end_nums2 = end_nums2b;
                    }
                    else
                    {
                      &nbs p; if (end_nums2a<0)
                        {
                      &nbs p;     end_nums2 = end_nums2b;
                         }
                        else
                      & nbsp; {
                      &nbs p;     end_nums2 = end_nums2a;
                         }
                    }
                    tmpStr = sTotalSubM.Substring( end_nums2-1,1 );
                    if ( tmpStr == """ || tmpStr == "'" )
                    {
                      &nbs p; end_nums2 = end_nums2 - 1;
                    }
                    string tmpPicStr = sTotalSubM.Substring( end_n12,end_nums2 - end_n12 );
                    if ( tmpPicStr.IndexOf( "http://" ) < 0 )
                    {
                      &nbs p; if ( tmpPicStr.IndexOf( "/" ) == 0 )
                        {
                      &nbs p;     tmpPicStr = urlch1 + tmpPicStr;
                     & nbsp;  }
                        else
                      & nbsp; {                            
                            int linshiIntNum = 0;
                      &nb sp;     int flags = 0;
                      &nb sp;     string urlChange = subUrl;
                     &nbs p;      while( tmpPicStr.IndexOf( "../" ) >= 0 )
                            {
                      &nbs p;         tmpPicStr = tmpPicStr.Substring( tmpPicStr.IndexOf("../") + 3 );
                      &nb sp;         linshiIntNum = linshiIntNum + 1;
                      &nb sp;         flags = flags + 1;
                      &nb sp;     }
                            while( ( urlChange.LastIndexOf( "/" ) >= 0 ) && ( linshiIntNum >= 0 ) )
                            {
                      &nbs p;         urlChange = urlChange.Substring( 0,urlChange.LastIndexOf( "/" ) );
                      &nb sp;         linshiIntNum = linshiIntNum - 1;
                      &nb sp;     }
                            if ( flags == 0 )
                            {
                      &nbs p;         tmpPicStr = urlch2 + "/" + tmpPicStr;
                     & nbsp;      }
                            else
                      & nbsp;     {
                      &nbs p;         tmpPicStr = urlChange + "/" + tmpPicStr;
                     & nbsp;      }
                        }
                    }
                    //tmpPicStr = tmpPicStr.ToLower();
                    string tmpPicStrTmp = tmpPicStr.ToLower ();
                    //if ( tmpPicStr.IndexOf( ".jpg" ) > 0 || tmpPicStr.IndexOf( ".gif" ) > 0 || tmpPicStr.IndexOf( ".bmp" ) > 0 )
                    if ( tmpPicStrTmp.IndexOf( ".jpg" ) > 0 || tmpPicStrTmp.IndexOf( ".gif" ) > 0 || tmpPicStrTmp.IndexOf( ".bmp" ) > 0 )
                    {
                      &nbs p; rePicStr = rePicStr + "||" + tmpPicStr ;
                      &nbs p; int flagN2 = tmpPicStr.LastIndexOf( "/" );
                      &nb sp; string fileN2 = picHtml + tmpPicStr.Substring( flagN2 );
                      &nb sp; sTotalSubM = sTotalSubM.Substring( 0,end_nums2 ) + ">******" + fileN2 + "******<" + sTotalSubM.Substring( end_nums2 );
                      &nb sp; begin_nums2 = sTotalSubM.IndexOf( "src=", end_nums2 + fileN2.Length + 22 );
                    }
                    else
                    {
                      &nbs p; begin_nums2 = sTotalSubM.IndexOf( "src=", end_nums2 + 4 );                       
                    }                   
                }
                if ( rePicStr.Length > 2 ) 
                    rePicStr =  rePicStr.Substring(2);              
                //内容处理 格式化关键标记
                while( sTotalSubM.IndexOf( "<P" ) >= 0 )
                {
                    sTotalSubM = sTotalSubM.Substring( 0,sTotalSubM.IndexOf( "<P" ) ) + "|****|<" + sTotalSubM.Substring( sTotalSubM.IndexOf( "<P" ) + 2 );
                }
                while( sTotalSubM.IndexOf( "<p" ) >= 0 )
                {
                    sTotalSubM = sTotalSubM.Substring( 0,sTotalSubM.IndexOf( "<p" ) ) + "|****|<" + sTotalSubM.Substring( sTotalSubM.IndexOf( "<p" ) + 2 );
                }
                while( sTotalSubM.IndexOf( "</P" ) >= 0 )
                {
                    sTotalSubM = sTotalSubM.Substring( 0,sTotalSubM.IndexOf( "</P" ) ) + "|****|<" + sTotalSubM.Substring( sTotalSubM.IndexOf( "</P" ) + 3 );
                }
                while( sTotalSubM.IndexOf( "</p" ) >= 0 )
                {
                    sTotalSubM = sTotalSubM.Substring( 0,sTotalSubM.IndexOf( "</p" ) ) + "|****|<" + sTotalSubM.Substring( sTotalSubM.IndexOf( "</p" ) + 3 );
                }
                while( sTotalSubM.IndexOf( "<br" ) >=0 )
                {
                    sTotalSubM = sTotalSubM.Substring( 0,sTotalSubM.IndexOf( "<br" ) ) + "+****+<" + sTotalSubM.Substring( sTotalSubM.IndexOf( "<br" ) + 3 );
                }
                while( sTotalSubM.IndexOf( "<BR" ) >= 0 )
                {
                    sTotalSubM = sTotalSubM.Substring( 0,sTotalSubM.IndexOf( "<BR" ) ) + "+****+<" + sTotalSubM.Substring( sTotalSubM.IndexOf( "<BR" ) + 3 );
                }
                while( sTotalSubM.IndexOf( "<Br" ) >= 0 )
                {
                    sTotalSubM = sTotalSubM.Substring( 0,sTotalSubM.IndexOf( "<Br" ) ) + "+****+<" + sTotalSubM.Substring( sTotalSubM.IndexOf( "<Br" ) + 3 );
                }
                while( sTotalSubM.IndexOf( "<bR" ) >= 0 )
                {
                    sTotalSubM = sTotalSubM.Substring( 0,sTotalSubM.IndexOf( "<bR" ) ) + "+****+<" + sTotalSubM.Substring( sTotalSubM.IndexOf( "<bR" ) + 3 );
                }
                //去除html标记
                int linshiInt1 = sTotalSubM.IndexOf( "<" );
                int linshiInt2 = sTotalSubM.IndexOf( ">" );           
                if ( linshiInt2 < linshiInt1 )
                {
                    sTotalSubM = sTotalSubM.Substring( linshiInt2 + 1 );
                }
                int linshiInt11 = sTotalSubM.LastIndexOf( "<" );
                int linshiInt12 = sTotalSubM.LastIndexOf( ">" );
                if ( linshiInt12 < linshiInt11 )
                {
                    sTotalSubM = sTotalSubM.Substring( 0,linshiInt12 + 1 );
                }
                linshiInt1 = sTotalSubM.IndexOf( "<" );
                while ( linshiInt1 >= 0 )
                {
                    linshiInt2 = sTotalSubM.IndexOf( ">",linshiInt1 );
                    if ( linshiInt2 >= 0 )
                    {              
                        sTotalSubM = sTotalSubM.Substring( 0,linshiInt1 ) + sTotalSubM.Substring( linshiInt2 + 1 );
                    }
                    else
                    {
                      &nbs p; sTotalSubM = sTotalSubM.Substring( 0,linshiInt1 );
                    }
                    linshiInt1 = sTotalSubM.IndexOf("<");
                }
                //还原关键标记
                int linshiInt3 = 0;
                int linshiInt4 = 0;
                while( sTotalSubM.IndexOf( "+****+" ) >= 0 )
                {
                    sTotalSubM = sTotalSubM.Substring( 0,sTotalSubM.IndexOf( "+****+" ) ) + "<br> " + sTotalSubM.Substring( sTotalSubM.IndexOf( "+****+" ) + 9 );
                }
                while( sTotalSubM.IndexOf( "|****|" ) >= 0 )
                {
                    sTotalSubM = sTotalSubM.Substring( 0,sTotalSubM.IndexOf( "|****|" ) ) + "<br> " + sTotalSubM.Substring( sTotalSubM.IndexOf( "|****|" ) + 9 );
                }
                while( sTotalSubM.IndexOf( "******" ) >= 0 )
                {
                    linshiInt3 = sTotalSubM.IndexOf( "******" ) + 9;
                    linshiInt4 = sTotalSubM.IndexOf( "******",linshiInt3 );
                    if ( linshiInt4 >= 0 )
                    {
                      &nbs p; int tmpPos = sTotalSubM.IndexOf( "******" );
                      &nb sp; string tmpStr1 = sTotalSubM.Substring( 0,tmpPos );
                        string tmpStr2 = sTotalSubM.Substring( linshiInt3,linshiInt4 - linshiInt3 );
                      &nb sp; string tmpStr3 = sTotalSubM.Substring( linshiInt4 + 9 );
                      &nb sp; sTotalSubM = tmpStr1 + "<img src=" + tmpStr2 + ">" + tmpStr3;
                    }
                    else
                    {
                      &nbs p; break;
                    }
                }
                //去除内容中的标题
                if ( sTotalSubM.IndexOf( subTitle ) >= 0 )
                {
                    sTotalSubM = sTotalSubM.Substring( 0,sTotalSubM.IndexOf( subTitle ) ) + sTotalSubM.Substring( sTotalSubM.IndexOf( subTitle ) + subTitle.Length );
                }
                reContentStr = sTotalSubM;
                //调用下载图片功能
                //下载图片到指定目录
                string[] img_Url = new PublicFun().split( rePicStr,"||" );
                for ( int i=0;i<img_Url.Length;i++ )
                {
                    if ( img_Url[i] != "" )
                    {
                      &nbs p; new PublicFun().Get_Img( img_Url[i],10000,root + "\images\" + img_Url[i].Substring( img_Url[i].LastIndexOf("/")+1 ) );
                    }
                }
            }
            return reContentStr;
        }

 

  以上方法返回要取得的信息,包括标题内容,图片地址等。

  下载页面中图片:

//下载图片
        public void Get_Img(string a_strUrl,int timeout,string filepath)
        {
            try
            {
HttpWebRequest myReq = (HttpWebRequest) HttpWebRequest.Create(a_strUrl) ;
                myReq.Timeout = timeout;
                HttpWebResponse HttpWResp = (HttpWebResponse)myReq.GetResponse();        
                Stream myStream = HttpWResp.GetResponseStream () ;         
                Bitmap map = new Bitmap( myStream );
                PictureBox picB = new PictureBox ();
                picB.Image = (Image) map;
                string path = filepath.Substring( 0,filepath.LastIndexOf( "\" ) );
                if (!Directory.Exists(path))
                {
                    CreateDir( path );
                }               
                picB.Image.Save (filepath);               
            }
            catch(Exception exp)
            {
                string ss = exp.Message;
        WriteLog( filepath.Substring(0,filepath.LastIndexOf("\")) + "\error.log",a_strUrl + "--" + ss + " ");       
            }
        }

 

  保存文件或入库

  上面取得的信息可以按自己的要求保存。

  ****设计的时候没有使用url按层次循 环抓取,这样定义抓取url效率更高,速度更快。

  注:此版本只提供静态文件存储功能,不提供数据库接口,不提供自定义网站功能。

  本程序运行需要先安 装.net 框架1.1。

 

 

  获取页面内容后,分析页面中连接地址取到要抓取的url:

//处理页面标题和链接
        public string SniffWebUrl( string urlStr,string blockB,string blockE )
        {      
            string urlch1 = "";
            string urlch2 = "";                   
            int end_n1 = 0;
            int end_nums = 0;
            int end_nums1 = 0;
            int end_nums2 = 0;
            int end_nums3     = 0;           
            string reUTStr = "";
            string reTitle = "";
            string ret = "";          
            try
            {
                int pos01 = urlStr.IndexOf( "." );
                int pos02 = urlStr.LastIndexOf( "/" );
                if( pos01 < 0 )
                {
                    return "";
                }
                if( pos02 < 0 )
                {
                    return "";
                }
                int pos03 = urlStr.IndexOf( "/",pos01 );
                if ( pos03 < 0 )
                {
                    urlch1 = urlStr;
                    urlch2 = urlStr;
                }
                else
                {
                    urlch1 = urlStr.Substring( 0,pos03 );
                    urlch2 = urlStr.Substring( 0,pos02 );
                }
                string tmpAllStr = new PublicFun().Get_Http( urlStr ,time1);
                int pos1 = tmpAllStr.IndexOf( blockB );
                int pos2 = tmpAllStr.IndexOf( blockE,pos1 + blockB.Length );
                if ( pos1>0 && pos2>0 && pos2>pos1 )
                {
                    ret = tmpAllStr.Substring( pos1 + blockB.Length,pos2 - pos1 - blockB.Length );
                    ret = ret.Substring( ret.IndexOf( "<" ));
                    while( ret.IndexOf( "<A" ) >= 0 )
                    {
                      &nbs p; ret = ret.Substring( 0,ret.IndexOf( "<A" ) ) + "<a" + ret.Substring( ret.IndexOf( "<A" ) + 2 );
                    }
                    while( ret.IndexOf( "</A" ) >=0 )
                    {
                      &nbs p; ret = ret.Substring( 0,ret.IndexOf( "</A" ) ) + "</a" + ret.Substring( ret.IndexOf( "</A" ) + 3 );
                    }
                    while( ret.IndexOf( "Href=" ) >=0 )
                    {
                      &nbs p; ret = ret.Substring( 0,ret.IndexOf( "Href=" )) + "href=" + ret.Substring( ret.IndexOf( "Href=" ) + 5 );
                    }
                    while( ret.IndexOf( "HREF=" ) >=0 )
                    {
                      &nbs p; ret = ret.Substring( 0,ret.IndexOf( "HREF=" )) + "href=" + ret.Substring( ret.IndexOf( "HREF=" ) + 5 );
                    }
                    while( ret.IndexOf( "href='" ) >=0 )
                    {
                      &nbs p; ret = ret.Substring( 0,ret.IndexOf( "href='" )) + "href="" + ret.Substring( ret.IndexOf( "href='" ) + 6 );
                    }
                }      
                tmpAllStr = ret;     
                int begin_nums = tmpAllStr.IndexOf( "href=" );
                while ( begin_nums >= 0 )
                {              
                    string tmpStrA = "";
                    string tmpStrB = tmpAllStr.Substring( begin_nums + 5,1 );
                    if ( tmpStrB == """ )
                    {
                      &nbs p; end_n1 = begin_nums + 6;
                      &nb sp; if ( ( end_n1 + 1 ) > tmpAllStr.Length )
                        {
                      &nbs p;     return "";
                    &nbs p;   }
                        tmpStrA = tmpAllStr.Substring( begin_nums+6,1 );
                    }
                    else
                    {
                      &nbs p; end_n1 = begin_nums + 5;
                      &nb sp; tmpStrA = tmpStrB;
                    }
                    if ( tmpStrA == "#" )
                    {
                      &nbs p; tmpAllStr = tmpAllStr.Substring( end_n1 );
                      &nb sp; begin_nums = tmpAllStr.IndexOf( "href=" );
                    }
                    else
                    {                  
                        end_nums1 = tmpAllStr.IndexOf( " ",end_n1 );
                      &nb sp; end_nums2 = tmpAllStr.IndexOf( ">",end_n1 );
                      &nb sp; end_nums3 = tmpAllStr.IndexOf( "</a",end_nums2 );
                      &nb sp; if ( ( end_nums3 >= 0 ) && ( end_nums2 >= 0 ) )
                        {
                      &nbs p;     reTitle = tmpAllStr.Substring( end_nums2 + 1,end_nums3 - end_nums2 - 1 );
                      &nb sp;     if ( end_nums1 > end_nums2 )
                            {
                      &nbs p;         end_nums = end_nums2;
                     & nbsp;      }
                            else
                      & nbsp;     {
                      &nbs p;         if ( end_nums1 < 0 )
                                {
                      &nbs p;             end_nums = end_nums2;
                     & nbsp;          }
                                else
                      & nbsp;         {
                      &nbs p;             end_nums = end_nums1;
                     & nbsp;          }
                            }
                            string str4 = tmpAllStr.Substring( end_nums-1, end_nums - end_nums + 1 );
                      &nb sp;     if ( str4 =="""  || str4 == "'" )
                            {
                      &nbs p;         end_nums = end_nums - 1;
                      &nb sp;     }
                            string sTotalOne = tmpAllStr.Substring( end_n1,end_nums - end_n1 );
                      &nb sp;     if ( sTotalOne.IndexOf( "http://" ) <0 )
                            {
                      &nbs p;         if ( sTotalOne.IndexOf( "/" ) == 0 )
                                {
                      &nbs p;             sTotalOne = urlch1 + sTotalOne;
                     & nbsp;          }
                                else
                      & nbsp;         {                               
                                    int linshiIntNum = 0;
                      &nb sp;             int flags = 0;
                      &nb sp;             string urlChange = urlStr;;
                     &nb sp;              while( sTotalOne.IndexOf( "../" ) >= 0 )
                                    {
                      &nbs p;                 sTotalOne = sTotalOne.Substring( sTotalOne.IndexOf( "../" ) + 3 );
                      &nb sp;                 linshiIntNum = linshiIntNum + 1;
                      &nb sp;                 flags = flags +1;
                      &n bsp;             }
                                    while( ( urlChange.LastIndexOf( "/" ) >= 0 ) && ( linshiIntNum >= 0 ) )
                                    {
                      &nbs p;                 urlChange = urlChange.Substring( 0,urlChange.LastIndexOf( "/" ) );
                      &nb sp;                 linshiIntNum = linshiIntNum - 1;
                      &nb sp;             }
                                    if ( flags == 0 )
                                    {
                      &nbs p;                 sTotalOne = urlch2 + "/" + sTotalOne;
                     & nbsp;              }
                                    else
                      & nbsp;             {
                      &nbs p;                 sTotalOne = urlChange + "/" + sTotalOne;
                     & nbsp;              }
                                }
                            }
                            reUTStr = reUTStr + new PublicFun().RemoveHtmlCode( reTitle ) + sTotalOne;
                     & nbsp;      tmpAllStr = tmpAllStr.Substring( end_nums3 + 4 );
                      &nb sp;     begin_nums = tmpAllStr.IndexOf( "href=" );
                      &nb sp; }
                        else
                      & nbsp; {
                      &nbs p;     begin_nums = - 1;
                      &nb sp; }                   
                    }
                }
                return reUTStr;
            }
            catch( Exception e)
            {
                return "";
            }
        }



相关教程