I am injecting two classes in my controller.

In the get request, when I put a break point, I can see there is an instance being retrieved in the constructor .

However in the post action, the instance is null ?

here is my controller class;

using BethanyPieShop.Models;
using Microsoft.AspNetCore.Mvc;

namespace BethanyPieShop.Controllers
{
    public class OrderController : Controller
    {
        public IOrderRepository _orderRepository { get; set; }
        public ShoppingCart _shoppingCart { get; set; }

        public OrderController(IOrderRepository _orderRepository, ShoppingCart _shoppingCart)
        {
            _orderRepository = _orderRepository;
            _shoppingCart = _shoppingCart;
        }
        public IActionResult Checkout()
        {

            return View();
        }

        [HttpPost]
        public IActionResult Checkout(Order order)
        {
            // Null here _shoppingCart
            var items = _shoppingCart.GetShoppingCartItems();
            _shoppingCart.ShoppingCartItems = items;

            if (_shoppingCart.ShoppingCartItems.Count == 0)
            {
                ModelState.AddModelError("", "Your cart is empty, add some pies first");
            }

            if (ModelState.IsValid)
            {
                _orderRepository.CreateOrder(order);
                _shoppingCart.ClearCart();
                return RedirectToAction("CheckoutComplete");
            }
            return View(order);
        }


        public IActionResult CheckoutComplete()
        {
            ViewBag.CheckoutCompleteMessage = ", thanks for your order. You'll soon enjoy our delicious pies!";
            return View();
        }


    }
}

I registered the services in the main class:

builder.Services.AddScoped<IOrderRepository, OrderRepository>();
builder.Services.AddScoped<ShoppingCart>();

CodePudding user response：

You are setting a variable with the same name. Without using a 'this.' statement. Try changing the following from

public OrderController(IOrderRepository _orderRepository, ShoppingCart _shoppingCart)
{
    _orderRepository = _orderRepository;
    _shoppingCart = _shoppingCart;
}

to

public OrderController(IOrderRepository orderRepository, ShoppingCart shoppingCart)
    {
        _orderRepository = orderRepository;
        _shoppingCart = shoppingCart;
    }

CodePudding user response：

So I think you should use this. Like this:

public OrderController(IOrderRepository _orderRepository, ShoppingCart _shoppingCart)
    {
        this._orderRepository = _orderRepository;
        this._shoppingCart = _shoppingCart;
    }