protected override Page DowloadContent(Request request, ISpider spider)
        {
            Site site = spider.Site;

            try
            {
                lock (this)
                {
                    if (_webDriver == null)
                    {
                        _webDriver = WebDriverUtil.Open(_browser, _option);
                    }

                    if (!_isLogined && SignIn != null)
                    {
                        _isLogined = SignIn.Handle(_webDriver as RemoteWebDriver);
                        if (!_isLogined)
                        {
                            throw new SpiderException("Login failed. Please check your login codes.");
                        }
                    }
                }

                //中文乱码URL
                Uri    uri     = request.Url;
                string query   = string.IsNullOrEmpty(uri.Query) ? "" : $"?{HttpUtility.UrlPathEncode(uri.Query.Substring(1, uri.Query.Length - 1))}";
                string realUrl = $"{uri.Scheme}://{uri.DnsSafeHost}{(uri.Port == 80 ? "" : ":" + uri.Port)}{uri.AbsolutePath}{query}";

                var domainUrl = $"{uri.Scheme}://{uri.DnsSafeHost}{(uri.Port == 80 ? "" : ":" + uri.Port)}";
                var options   = _webDriver.Manage();
                if (options.Cookies.AllCookies.Count == 0 && spider.Site.Cookies.PairPart.Count > 0)
                {
                    _webDriver.Url = domainUrl;
                    options.Cookies.DeleteAllCookies();
                    foreach (var c in spider.Site.Cookies.PairPart)
                    {
                        options.Cookies.AddCookie(new Cookie(c.Key, c.Value));
                    }
                }

                if (UrlHandler != null)
                {
                    realUrl = UrlHandler(realUrl);
                }

                NetworkCenter.Current.Execute("wd-d", () =>
                {
                    _webDriver.Navigate().GoToUrl(realUrl);

                    NavigateCompeleted?.Handle((RemoteWebDriver)_webDriver);
                });

                Thread.Sleep(_webDriverWaitTime);

                Page page = new Page(request, spider.Site.ContentType, site.RemoveOutboundLinks ? site.Domain : null)
                {
                    Content   = _webDriver.PageSource,
                    TargetUrl = _webDriver.Url,
                    Title     = _webDriver.Title
                };

                // 结束后要置空, 这个值存到Redis会导置无限循环跑单个任务
                request.PutExtra(Request.CycleTriedTimes, null);
                return(page);
            }
            catch (DownloadException)
            {
                throw;
            }
            catch (Exception e)
            {
                Page page = new Page(request, site.ContentType, null)
                {
                    Exception = e
                };
                return(page);
            }
        }