public IActionResult Checkout(ShippingDetails shippingDetails) { if (_cartProvider.Lines.Count() == 0) { ModelState.AddModelError("", "Извините, ваша корзина пуста!"); } if (ModelState.IsValid) { _orderProcessor.ProcessOrder(shippingDetails); _cartProvider.Clear(); return(View("Completed")); } else { return(View(shippingDetails)); } }