笨笨图片批量抓取下载 V0.2 beta[C# | WinForm | 正则表达式 | HttpWebRequest | Async异步编程]

         ///   <summary>
         ///  异步分析下载
         ///   </summary>
         private   void  AsyncAnalyzeAndDownload( string  url,  string  savePath)
        {
             this .uriString  =  url;
             this .savePath  =  savePath;

             #region  分析计时开始

            count  =   0 ;
            count1  =   0 ;
            freq  =   0 ;
            result  =   0 ;

            QueryPerformanceFrequency( ref  freq);
            QueryPerformanceCounter( ref  count);

             #endregion

             using  (WebClient wClient  =   new  WebClient())
            {
                AutoResetEvent waiter  =   new  AutoResetEvent( false );
                wClient.Credentials  =  CredentialCache.DefaultCredentials;
                wClient.DownloadDataCompleted  +=   new  DownloadDataCompletedEventHandler(AsyncURIAnalyze);
                wClient.DownloadDataAsync( new  Uri(uriString), waiter);
                 // waiter.WaitOne();      // 阻止当前线程，直到收到信号
            }
                
        }

         ///   <summary>
         ///  异步分析
         ///   </summary>
         protected   void  AsyncURIAnalyze(Object sender, DownloadDataCompletedEventArgs e)
        {
            AutoResetEvent waiter  =  (AutoResetEvent)e.UserState;
             try
            {
                 if  ( ! e.Cancelled  &&  e.Error  ==   null )
                {
                    
                     string  dnDir  =   string .Empty;
                     string  domainName  =   string .Empty;
                     string  uri  =  uriString;

                     // 获得域名  http://www.sina.com/
                    Match match  =  Regex.Match(uri,  @" ((http(s)?://)?)+[\w-.]+[^/] " ); // , RegexOptions.IgnoreCase
                    domainName  =  match.Value;

                     // 获得域名最深层目录  http://www.sina.com/mail/
                     if  (domainName.Equals(uri))
                        dnDir  =  domainName;
                     else
                        dnDir  =  uri.Substring( 0 , uri.LastIndexOf( ' / ' ));

                    dnDir  +=   ' / ' ;
                    
                     // 获取数据
                     string  pageData  =  Encoding.UTF8.GetString(e.Result);
                    List < string >  urlList  =   new  List < string > ();

                     // 匹配全路径
                    match  =  Regex.Match(pageData,  @" ((http(s)?://)?)+(((/?)+[\w-.]+(/))*)+[\w-./]+\.+( "   +  ImageType  +   " ) " );  // , RegexOptions.IgnoreCase
                     while  (match.Success)
                    {
                         string  item  =  match.Value;
                         // 短路径处理
                         if  (item.IndexOf( " http:// " )  ==   - 1   &&  item.IndexOf( " https:// " )  ==   - 1 )
                            item  =  (item[ 0 ]  ==   ' / '   ?  domainName : dnDir)  +  item;

                         if  ( ! urlList.Contains(item))
                        {
                            urlList.Add(item);
                            imgUrlList.Add(item);

                             // 实时显示分析结果
                            AddlbShowItem(item);

                             // 边分析边下载
                            WebRequest hwr  =  WebRequest.Create(item);
                            hwr.BeginGetResponse( new  AsyncCallback(AsyncDownLoad), hwr);
                             // hwr.Timeout = "0x30D40";         // 默认 0x186a0 -> 100000 0x30D40 -> 200000
                             // hwr.Method = "POST";
                             // hwr.ContentType = "application/x-www-form-urlencoded";
                             // hwr.MaximumAutomaticRedirections = 3;
                             // hwr.Accept ="image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, application/x-shockwave-flash, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword, */*";
                             // hwr.Accept = "image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, */*";
                             // IAsyncResult iar = hwr.BeginGetResponse(new AsyncCallback(AsyncDownLoad), hwr);
                             // iar.AsyncWaitHandle.WaitOne();
                        }
                        match  =  match.NextMatch();
                    }
                }
            }
             finally
            {
                waiter.Set();

                 #region  分析计时结束

                QueryPerformanceCounter( ref  count1);
                count  =  count1  -  count;
                result  =  ( double )(count)  /  ( double )freq;

                toolStripStatusLabel1.Text  =   " 分析完毕！ " ;
                toolStripStatusLabel2.Text  =   string .Format( "  | 分析耗时:{0}秒 " , result);
                Application.DoEvents();

                 #endregion

                 // 分析完毕
                isAnalyzeComplete  =   true ;
            }
        }

         ///   <summary>
         ///  异步接受数据
         ///   </summary>
         ///   <param name="asyncResult"></param>
         public    void  AsyncDownLoad(IAsyncResult asyncResult)  
        {
             #region  下载计时开始

             if  (cfreq  ==   0 )
            {
                QueryPerformanceFrequency( ref  cfreq);
                QueryPerformanceCounter( ref  ccount);
            }

             #endregion

            WebRequest request  =  (WebRequest)asyncResult.AsyncState;
             string  url  =  request.RequestUri.ToString();
             try
            {
                WebResponse response  =  request.EndGetResponse(asyncResult);
                 using  (Stream stream  =  response.GetResponseStream())
                {
                    Image img  =  Image.FromStream(stream);
                     string [] tmpUrl  =  url.Split( ' . ' );
                    img.Save( string .Concat(savePath,  " / " , DateTime.Now.ToString( " yyyyMMddHHmmssfff " ),  " . " , tmpUrl[tmpUrl.Length  -   1 ]));
                    img.Dispose();
                    stream.Close();
                }
                allDone.Set();

                 // 从未下载的列表中删除已经下载的图片
                imgUrlList.Remove(url);

                 // 更新列表框
                 int  indexItem  =   this .lbShow.Items.IndexOf(url);
                 if  (indexItem  >=   0   &&  indexItem  <=   this .lbShow.Items.Count)
                    SetlbShowItem(indexItem);
            }
             catch  (Exception)
            {
                imgUrlList.Remove(url);
            }
        }