.NET Core开发实战（第5课：依赖注入：良好架构的起点）--学习笔记（下）

services.AddSingleton<IOrderService>(new OrderService());
services.Replace(ServiceDescriptor.Singleton<IOrderService, OrderServiceEx>());// 替换掉注册的第一个实现

获取到服务实例：DependencyInjectionDemo.Services.OrderServiceEx:25560520

services.AddSingleton<IOrderService>(new OrderService());
services.AddSingleton<IOrderService, OrderServiceEx>();
services.RemoveAll<IOrderService>();// 移除所有 IOrderService 的注册

Unable to resolve service for type 'DependencyInjectionDemo.Services.IOrderService'

namespace DependencyInjectionDemo.Services
{

    public interface IGenericService<T>
    {

    }

    public class GenericService<T> : IGenericService<T>
    {
        public T Data { get; private set; }
        public GenericService(T data)
        {
            this.Data = data;
        }

    }
}

services.AddSingleton(typeof(IGenericService<>), typeof(GenericService<>));

// 在构造函数中添加两个入参，IOrderService 和 IGenericService
// 通过断点调试查看 genericService 的类型可得知，泛型的具体实现可以用容器里面的任意类型来替代
public WeatherForecastController(ILogger<WeatherForecastController> logger, IOrderService orderService, IGenericService<IOrderService> genericService)
{
    _orderService = orderService;
    _logger = logger;
}