/// <summary>
 /// 文件下载周期任务
 /// </summary>
 /// <returns></returns>
 public void DownLoadFileAsync()
 {
     while (true)
     {
         if (FilesQueue != null && FilesQueue.Count > 0)
         {
             string fileUrl       = FilesQueue.Dequeue();
             string fileLocalPath = LocalPath + Path.GetFileName(fileUrl);
             bool   ret           = _httpFile.HttpDownloadFileAsync(fileUrl, fileLocalPath);
             if (!ret)                        //失败
             {
                 FilesQueue.Enqueue(fileUrl); //重新加入下载任务
             }
             else
             {
                 _log.WriteLog("已成功下载文件" + fileUrl);
             }
         }
         Console.WriteLine(this.GetHashCode());
         Thread.Sleep(1000);
     }
 }