public IList <BannerView> GetBanners(int size) { var data = _cacheStorage.SortedSetRangeByRank <string, BannerView> (AdvertStaticResource.DBINDEX, AdvertStaticResource.BANNERKEY, stop: size); if (data == null || data.Count == 0) { var models = _advertRepository .GetList(x => true) .OrderByDescending(x => x.CreateTime).Take(size) .ToList(); data = BannerView.ToView(models); } return(data); }