/// <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);
            }
        }