將StoreContext DI注入到ProductService 類別中

並取代原先兩個取商品清單跟詳細資訊兩個action

using MyReact1.Domain;
using MyReact1.Models;

namespace MyReact1.Services
{
    public class ProductService
    {
        private readonly StoreContext dbContext;

        public ProductService(StoreContext dbContext)
        {
            this.dbContext = dbContext;
        }

        public ProductModel GetProductList()
        {
            var products = dbContext.Products;

            var model = new ProductModel();
            foreach (var product in products)
            {
                model.Products.Add(new ProductModel.ProductListItem
                {
                    Id = product.Id,
                    Description = product.Description,
                    Name = product.Name
                });
            }
            return model;
        }

        public ProductDetailsModel GetDetails(int id)
        {
            var product = dbContext.Products.Find(id);

            return new ProductDetailsModel
            {
                Id = product.Id,
                Name = product.Name,
                Description = product.Description,
                Price = product.Price
            };
        }

    }
}

改寫ProductController
將ProductService一樣透過DI注入方式引入到Controller做方法存取

using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using MyReact1.Models;
using MyReact1.Services;

namespace MyReact1.Controllers
{
    [Route("api/[controller]")]
    [ApiController]
    public class ProductController : ControllerBase
    {
        private readonly ProductService productService;

        public ProductController(ProductService productService)
        {
            this.productService = productService;
        }



        public IActionResult List()
        {
            ProductModel model = productService.GetProductList();
            return Ok(model);

        }
        //  -> /api/Product/10
        [HttpGet("{id}")]
        public IActionResult Details(int id)
        {
            return Ok(productService.GetDetails(id));

        }

    }
}

記得在Program.cs相關Dbcontext和Service都需要先進行服務註冊

在.net core服務註冊中生命週期(IoC容器生命週期)
又有細分為如下幾種
Transient:每次被請求都會創建新的實體
Transient objects are always different; a new instance is provided to every controller and every service.

Scoped:每次Web請求會創建一個新實體，直到web請求結束就銷毀。
Scoped objects are the same within a request, but different across different requests.

Singleton:一旦被創建實體就會持續一直用，直到應用停止才銷毀。
Singleton objects are the same for every object and every request.

更詳細可參考
.NET Core第12天_服務依賴注入_IoC容器生命週期_ConfigureServices
https://coolmandiary.blogspot.com/2021/07/net-core12iocconfigureservices.html