protected override void OnResume() { base.OnResume(); // If we haven't already loaded the products from the store, do it now if (listView.Adapter == null && !isFetching) { isFetching = true; ShowLoadingDialog(Resource.String.loading_data); var success = new Action <IEnumerable <Product>, Response>((products, response) => { isFetching = false; DismissLoadingDialog(); OnFetchedProducts(products.ToList()); }); var failure = new Action <RetrofitError>(error => { isFetching = false; OnError(error); }); if (collectionId != null) { SampleApplication.GetProducts(collectionId, success, failure); } else { SampleApplication.GetAllProducts(success, failure); } } }