private static void extractImages(List <HistoryImage> result, string indexPageHtml)
        {
            var doc = new HtmlDocument();

            doc.LoadHtml(indexPageHtml);
            var items = doc.DocumentNode.SelectNodes("//div[@class='item']");

            //HistoryImageProvider
            items.ToList().ForEach(node =>
            {
                var date = node.SelectSingleNode(".//em[1]").InnerText;
                if (!HistoryImageProvider.IsExist(date))
                {
                    try
                    {
                        var url = "https://bing.ioliu.cn" + node.SelectSingleNode(".//a[@class='mark']").Attributes["href"].Value;
                        result.Add(fetchSpecDayWallpaper(date, url));
                    }
                    catch (Exception ex)
                    {
                        Console.WriteLine(ex.Message);
                    }
                }
            });
        }
        private static void extractImages(List <HistoryImage> result, string indexPageHtml)
        {
            var doc = new HtmlDocument();

            doc.LoadHtml(indexPageHtml);
            var items = doc.DocumentNode.SelectNodes("//div[@class='item']");

            //HistoryImageProvider
            items.ToList().ForEach(node =>
            {
                var date = node.SelectSingleNode(".//em[1]").InnerText;
                if (!HistoryImageProvider.IsExist(date))
                {
                    try
                    {
                        var url        = "https://bing.ioliu.cn" + node.SelectSingleNode(".//a[@class='mark']").Attributes["href"].Value;
                        var detailHtml = HttpHelper.SendGet(url);
                        var detailDoc  = new HtmlDocument();
                        detailDoc.LoadHtml(detailHtml);
                        result.Add(new HistoryImage
                        {
                            Id          = Guid.NewGuid().ToString(),
                            ImageUrl    = detailDoc.DocumentNode.SelectSingleNode("//a[@class='ctrl download']").Attributes["href"].Value,
                            Title       = detailDoc.DocumentNode.SelectSingleNode("//p[@class='title']").InnerText.Trim(),
                            Description = detailDoc.DocumentNode.SelectSingleNode("//p[@class='sub']").InnerText.Trim(),
                            Date        = date,
                            AddDateTime = DateTime.Now.ToLongDateString(),
                            updateTime  = DateTime.Now.ToLongDateString(),
                            Url         = url,
                            Locate      = detailDoc.DocumentNode.SelectSingleNode("//p[@class='location']").InnerText.Trim(),
                        });
                    }
                    catch
                    {
                    }
                }
            });
        }