public async Task <ObservableCollection <CatalogItem> > GetCatalogAsync() { UriBuilder builder = new UriBuilder(GlobalSetting.Instance.CatalogEndpoint); builder.Path = "api/v1/catalog/items"; string uri = builder.ToString(); CatalogRoot catalog = await _requestProvider.GetAsync <CatalogRoot>(uri); if (catalog?.Data != null) { ServicesHelper.FixCatalogItemPictureUrl(catalog.Data); return(catalog.Data.ToObservableCollection <CatalogItem>()); } else { return(new ObservableCollection <CatalogItem>()); } }