决心用autofce是为了解决以前一个三层架构项目(DAL+IDAL+BLL)+mvc中，老是在控制器中　new BLL.名称.方法　，不想出现这个new　实例。
于是先做了小小实验，新建立一个解决方案，
类库
DAL中有一个userinfoDAL.cs
public class userinfoDAL:IDAL.IUserinfo
    {
        public string getUserType(int Id) {
            if (Id == 1) return "1号首长";
            return "政委";
        }
    }

 
类库IDAL中对应了一个接口　IUserinfo
public interface IUserinfo
    {
        string getUserType(int Id);
    }
}

 
建立一个mvc 3项目
public class HomeController : Controller
    {
        private IDAL.IUserinfo _userinfo;
        public HomeController(IDAL.IUserinfo userinfo) {
            _userinfo = userinfo;
        }

 
        public ActionResult Index()
        {
            ViewData["message"] = _userinfo.getUserType(1);
            return View();
        }

 
    }
想测试一下能不能显示几号首长，直接失败出错
也许是不懂写配置代码 Global.cs中
protected void Application_Start()
        {
            //注入
            ContainerBuilder builder = new ContainerBuilder();
            builder.RegisterControllers(Assembly.GetExecutingAssembly());
            builder.RegisterAssemblyTypes(Assembly.GetExecutingAssembly())
                .AsImplementedInterfaces();

            var container = builder.Build();
            DependencyResolver.SetResolver(new AutofacDependencyResolver(container));

            //注入代码结束

            AreaRegistration.RegisterAllAreas();

            // 默认情况下对 Entity Framework 使用 LocalDB
            Database.DefaultConnectionFactory = new SqlConnectionFactory(@"Data Source=(localdb)\v11.0; Integrated Security=True; MultipleActiveResultSets=True");

            RegisterGlobalFilters(GlobalFilters.Filters);
            RegisterRoutes(RouteTable.Routes);
        }

运行后错误是

None of the constructors found with 'Public binding flags' on type 'WEB.Controllers.HomeController' can be invoked with the available services and parameters:
Cannot resolve parameter 'IDAL.IUserinfo userinfo' of constructor 'Void .ctor(IDAL.IUserinfo)'.