建立一個Services目錄, 然後建立一個 ProductService.cs類
我們把獲取資料的程式碼整理成一個ProductService, 然後保證程式執行的時候, 操作的是同一批資料:

namespace CoreBackend.Api.Services
{
    public class ProductService
    {
        public static ProductService Current { get; } = new ProductService();

        public List<Product> Products { get; }

        private ProductService()
        {
            Products = new List<Product>
            {
                new Product
                {
                    Id = 1,
                    Name = "牛奶",
                    Price = 2.5f
                },
                new Product
                {
                    Id = 2,
                    Name = "麵包",
                    Price = 4.5f
                },
                new Product
                {
                    Id = 3,
                    Name = "啤酒",
                    Price = 7.5f
                }
            };
        }
    }
}
 

然後修改一下ProductController.cs裡面的程式碼:

namespace CoreBackend.Api.Controllers
{
    [Route("api/[controller]")]
    public class ProductController: Controller
    {
        [HttpGet]
        public JsonResult GetProducts()
        {
            return new JsonResult(ProductService.Current.Products);
        }
    }
}
 

也是同樣的執行效果.