Autofac依赖注入

Autofac是什么？
Autofac是一种IOC容器，那么什么是IOC容器呢？

先说一下两个概念IOC和DI，我的理解：

　　① IOC：调用者不再创建(不自己new)被调用者的实例，而是交给容器去创建(AutoFac就充当这里的容器)，这就是控制反转。

　　② DI：容器创建好的实例再注入调用者的过程，就是依赖注入（比如：属性注入、构造函数注入等）。

控制反转
控制反转背后的核心思想是, 我们不再将类绑定在应用里,让类自己去 "new up" 他们的依赖, 而是反过来在类的构造方法中将依赖传递进去

构建应用

Repository层

public interface IUserRepository
    {
        List<User> GetModelList(int isEnabled = 1);

    }

 public partial class UserRepository : IUserRepository
    {
        public List<User> GetModelList(int isEnabled = 1)
        {
            var sql = $"select * from [User] where IsEnabled=@IsEnabled ";
            return DapperHelper.GetModelList<User>(sql, new { IsEnabled = isEnabled });
        }
    }

Service层

public interface IUserService : IBaseService<User>
    {
        List<User> GetModelList(int isEnabled = 1);

    }


 public partial class UserService : BaseService<User>, IUserService
    {
        private readonly IUserRepository _userRepository;

        public UserService(IUserRepository userRepository, IBaseRepository<User> baseRepository) : base(baseRepository)
        {
            this._userRepository = userRepository;
        }

        public List<User> GetModelList(int isEnabled = 1)
        {
            return this._userRepository.GetModelList(isEnabled);
        }

    }

Web层（注意引用）

public class AutofacConfig
    {
        /// <summary>
        /// 负责调用autofac框架实现业务逻辑层和数据仓储层程序及中的类型对象的创建
        /// 负责创建Web控制器类的对象（调用控制器中的有参构造函数）,接管DefaultControllerFactory的工作
        /// </summary>

        public static void Register()

        {

            // 实例化一个autofac的创建容器

            var builder = new ContainerBuilder();

            SetupResolveRules(builder);

            //注册所有的Controllers

            builder.RegisterControllers(Assembly.GetExecutingAssembly()).PropertiesAutowired();

            // 创建一个autofac的容器

            var container = builder.Build();

            // 控制器对象由autofac来创建

            DependencyResolver.SetResolver(new AutofacDependencyResolver(container));

        }



        /// <summary>
        /// 设置配置规则
        /// </summary>
        /// <param name="builder"></param>

        public static void SetupResolveRules(ContainerBuilder builder)

        {
            //注册Controller

            // 告诉autofac框架，将来要创建的控制器类存放在哪个程序集
            var controllerAssmbly = Assembly.Load("Web");
            builder.RegisterControllers(controllerAssmbly);

            //批量注册所有仓储Repository && Service
            var assemblies = new Assembly[] { Assembly.Load("AutoFac.Repository"), Assembly.Load("AutoFac.Service") }; //声明一个可变数组，可以加载多个类库
            builder.RegisterAssemblyTypes(assemblies).Where(t => !t.IsAbstract).AsImplementedInterfaces().PropertiesAutowired(); // 获取所有相关类库的程序集

            //注册泛型仓储
            builder.RegisterGeneric(typeof(BaseRepository<>)).As(typeof(IBaseRepository<>));
            //builder.RegisterGeneric(typeof(BaseService<>)).As(typeof(IBaseService<>));

            //注册log模块
            //builder.RegisterModule(new LoggingModule());

        }

    }

控制器调用

public class HomeController : Controller
    {

        private readonly IUserService _userService;
        private readonly IRoleService _roleService;
        public HomeController(IUserService userService, IRoleService roleService)
        {
            _userService = userService;
            _roleService = roleService;
        }

        public ActionResult Index()
        {
            var userModel = _userService.GetModel("085AC7C7-94BE-4A41-93C7-C207939714B9");

            var userList = _userService.GetModelList();

            var umodel = _userService.Get("085AC7C7-94BE-4A41-93C7-C207939714B9");

            var predicateList = new List<IPredicate>();
            predicateList.Add(Predicates.Field<User>(u => u.IsEnabled, Operator.Eq, 1));

            var userlist = _userService.GetList(new { IsEnabled = 1 }, new List<ISort>() { new Sort { PropertyName = "CreatTime", Ascending = false } });

            return View();
        }

        public ActionResult About()
        {
            ViewBag.Message = "Your application description page.";

            return View();
        }

        public ActionResult Contact()
        {
            ViewBag.Message = "Your contact page.";

            return View();
        }
    }