public IActionResult AddItem([FromForm] SaleItem saleItem) { if (ModelState.IsValid) { Sale sale = _salesRepository.GetSaleById(saleItem.SaleId); _salesRepository.AddItem(saleItem); return(RedirectToAction("Details", "Sale", new { id = saleItem.SaleId })); } SaleItemViewModel saleItemViewModel = new SaleItemViewModel { ProductNamesListItem = new List <SelectListItem>(), SaleItem = saleItem }; saleItemViewModel.ProductNamesListItem = GetProductNamesListItem(); return(View(saleItemViewModel)); }