Autofac小例子

AutoFac是.net平台下的IOC容器產品。今天學習一下它的使用方法。

1.最簡單的使用。

    public interface ITestDao
    {
        string SayHello();
    }
    public class TestDao : ITestDao
    {
        public string SayHello()
        {
            return "hello world!";
        }
    }
    

            var builder = new ContainerBuilder();
            builder.RegisterType<TestDao>().As<ITestDao>();

            IContainer container = builder.Build();
            var tdao = container.Resolve<ITestDao>();
            string saystr = tdao.SayHello();        

builder.RegisterType<TestDao>().As<ITestDao>();注冊TestDao是ITestDao的實現。
然后下面進行調用就行。

2.跟mvc一起使用

    public interface ITestDao
    {
        string SayHello();
    }
    public class TestDao : ITestDao
    {
        public string SayHello()
        {
            return "hello world!";
        }
    }
    

    public class HomeController : Controller
    {

        private ITestDao _testDao;

        public HomeController(ITestDao testDao) 
        {
            this._testDao = testDao;
        }

        public ActionResult Index()
        {

            string saystr = _testDao.SayHello();

            return View();
        }

    }

在Global.asax里需要添加幾行代碼

　　public class MvcApplication : System.Web.HttpApplication
    {
        protected void Application_Start()
        {
            //依賴注入
            var builder = new ContainerBuilder();
            SetupResolveRules(builder);
            builder.RegisterControllers(Assembly.GetExecutingAssembly());
            var container = builder.Build();
            DependencyResolver.SetResolver(new AutofacDependencyResolver(container));


            AreaRegistration.RegisterAllAreas();

            WebApiConfig.Register(GlobalConfiguration.Configuration);
            FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
            RouteConfig.RegisterRoutes(RouteTable.Routes);
            BundleConfig.RegisterBundles(BundleTable.Bundles);
        }

        private void SetupResolveRules(ContainerBuilder builder)
        {
            builder.RegisterType<TestDao>().As<ITestDao>();
        }
    }

3.將注冊代碼放進配置文件。

    public interface ITestDao
    {
        string SayHello();
    }
    public class TestDao : ITestDao
    {
        public string SayHello()
        {
            return "hello world!";
        }
    }
    

    public class HomeController : Controller
    {

        private ITestDao _testDao;

        public HomeController(ITestDao testDao) 
        {
            this._testDao = testDao;
        }

        public ActionResult Index()
        {

            string saystr = _testDao.SayHello();

            return View();
        }

    }

在Global.asax里需要添加幾行代碼

　　　　protected void Application_Start()
        {
            //依賴注入
            var builder = new ContainerBuilder();
            builder.RegisterModule(new ConfigurationSettingsReader("autofac")); 
            builder.RegisterControllers(Assembly.GetExecutingAssembly());
            var container = builder.Build();
            DependencyResolver.SetResolver(new AutofacDependencyResolver(container));


            AreaRegistration.RegisterAllAreas();

            WebApiConfig.Register(GlobalConfiguration.Configuration);
            FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
            RouteConfig.RegisterRoutes(RouteTable.Routes);
            BundleConfig.RegisterBundles(BundleTable.Bundles);
        }

在Web.config添加配置文件

<configSections>
    <section name="autofac" type="Autofac.Configuration.SectionHandler, Autofac.Configuration" />
  </configSections>
<autofac defaultAssembly="MvcApplication11">
    <components>
      <component type="MvcApplication11.Models.TestDao" service="MvcApplication11.Models.ITestDao" />
    </components>
  </autofac>

 4.系統自動注冊，省略掉手工的配置和xml文件配置。（2014-07-16補充）

寫一個基礎接口，讓你所有的接口都實現此接口，此接口起到的作用僅僅是個標識作用。

    public interface IAutofac//標識接口
    {

    }
    public interface ITestDao : IAutofac
    {
        string SayHello();
    }
    public class TestDao : ITestDao
    {
        public string SayHello()
        {
            return "hello world!";
        }
    }
    
    public class HomeController : Controller
    {

        private ITestDao _testDao;

        public HomeController(ITestDao testDao) 
        {
            this._testDao = testDao;
        }

        public ActionResult Index()
        {

            string saystr = _testDao.SayHello();

            return View();
        }

    }

然后更改Global.asax里面的代碼，AppDomain.CurrentDomain.GetAssemblies()獲取當前程序域里所有的程序集，下面讓RegisterAssemblyTypes自動注冊所有繼承了IAutofac的接口。

        protected void Application_Start()
        {
            //依賴注入
            var builder = new ContainerBuilder();
            //builder.RegisterModule(new ConfigurationSettingsReader("autofac"));
            
            var assemblys = AppDomain.CurrentDomain.GetAssemblies().ToList();
            builder.RegisterAssemblyTypes(assemblys.ToArray())
                .Where(e => typeof(IAutofac).IsAssignableFrom(e) && e != typeof(IAutofac))
                .AsImplementedInterfaces()
                .InstancePerLifetimeScope();

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



            AreaRegistration.RegisterAllAreas();

            WebApiConfig.Register(GlobalConfiguration.Configuration);
            FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
            RouteConfig.RegisterRoutes(RouteTable.Routes);
            BundleConfig.RegisterBundles(BundleTable.Bundles);
        }