/// <summary>
 /// 后台任务 提示头条文章信息
 /// </summary>
 /// <returns></returns>
 public async static Task UpdateTopStories()
 {
     APIService api = new APIService();
     var t = await api.GetLatestStories(true);
     if (t != null)
     {
         UpdateTile(t);
         UpdateBadge(t);
         ShowToast(t);
     }
 }
 public async static Task PullLatestStories()
 {
     APIService api = new APIService();
     var t = await api.GetLatestStories();
 }
        /// <summary>
        /// 拉取最新文章
        /// </summary>
        /// <returns></returns>
        public async static Task PullLatestStories()
        {
            APIService api = new APIService();
            var t = await api.GetLatestStories();

            //将当天未读文章更新到 badge
            int un_readed = 0;
            
            t.Stories.ToList().ForEach(s => { if (!DataShareManager.Current.ReadedList.Contains(s.ID)) un_readed++; });


            var updater = BadgeUpdateManager.CreateBadgeUpdaterForApplication();
            if (un_readed != 0)
            {
                var badgexml = new BadgeNumericNotificationContent((uint)un_readed);

                var n = badgexml.CreateNotification();
                n.ExpirationTime = DateTime.Now.AddDays(7);

                updater.Update(n);
            }
            else
            {
                updater.Clear();
            }
        }