[Solution] 使用Autofac在MVC、Web API、WCF中实现IOC

本来想聊一下面试过程的,1个星期面了6家,4家当场给offer,2家技术通过(1家没下文,1家复试).从中也学习到一些东西,先还是继续Coding吧.

官网:http://autofac.org/

下载:Install-Package Autofac -Version 3.5.2

Autofac是轻量级的开源IOC容器,传说是速度最快的一个,同类的框架还有用过Castle Windsor、StructureMap、Unity、Spring.Net等.

本节目录

• Hello World
• 注入高级对象
• 读取配置文件注入
• 结合ASP.NET MVC
• 结合ASP.NET Web API
• 结合WCF

Hello World

1.建立项目

CA:一个控制台项目,引用Nuget Autofac包.

2.建立一个依赖外部的类

    public class Test
    {
        public Test(string str)
        {
            Console.WriteLine("hello " + str);
        }
    }

3.根据参数名直接注入

static void Main(string[] args)
{
　　//创建容器工厂
    var builder = new ContainerBuilder();
   //注册Test类型到工厂中
    builder.RegisterType<Test>();
　　//通过工厂创建容器
    using (var container = builder.Build())
    {
　　　　//解析Test并返回Test实例
       container.Resolve<Test>(new NamedParameter("str", "world"));
    }
    Console.ReadKey();
}

过程:首先需要创建容器工厂,然后将各种类型注册到工厂中,再创建容器,通过容器实例化对象.

注入高级对象

添加1个构造函数

public Test(ISay say)
{
    Console.WriteLine("say:" + say.Get());
}

接口及其实现

    public class Say : ISay
    {
        public string Get()
        {
            return "hello world";
        }
    }

    public interface ISay
    {
        string Get();
    }

注入实现(Autofac会自动装配)

        static void Main(string[] args)
        {
            var builder = new ContainerBuilder();

            builder.RegisterType<Test>();
            builder.RegisterType<Say>().As<ISay>();
            using (var container = builder.Build())
            {
                container.Resolve<Test>();
            }
            Console.ReadKey();
        }

略作修改

　　 　　public Test(Say say)//将接口改为指定具体实现类
        {
            Console.WriteLine("say:" + say.Get());
        }

此时运行代码会报错,因为在容器中我们只注册了ISay接口.改为As<Say>或以下方式

builder.RegisterType<Say>().As<ISay>().AsSelf();

对象生命周期

注册到工厂的类型默认都调用InstancePerDependency方法.实现每个依赖都创建1个新实例

单例模式:

            builder.RegisterType<Test>().SingleInstance();

读取配置文件注入

需要引用Nuget Autofac.Configuration包

注册类型代码

builder.RegisterModule(new ConfigurationSettingsReader("autofac"));

App.config

  <configSections>
    <section name="autofac" type="Autofac.Configuration.SectionHandler, Autofac.Configuration" />
  </configSections>
  <autofac defaultAssembly="CA">
    <components>
      <component type="CA.Say, CA" service="CA.ISay" />
      <component type="CA.Say, CA" service="CA.Say" />
    </components>
  </autofac>

service相当于As<T>中的T

结合ASP.NET MVC

1.Install-Package Autofac.Mvc5

2.Application_Start事件添加此方法

        protected void Application_Start(object sender, EventArgs e)
        {
            #region 1.MVC Autofac注入
            var builder = new ContainerBuilder();
            //类名.EndsWith("Controller")
            builder.RegisterControllers(Assembly.GetExecutingAssembly());
            //这样既支持接口 又支持自己的类型
            builder.RegisterAssemblyTypes(Assembly.GetExecutingAssembly())
                .AsImplementedInterfaces().AsSelf();
            //容器
            var container = builder.Build();
            //注入改为Autofac注入
            DependencyResolver.SetResolver(new AutofacDependencyResolver(container));
            #endregion

            #region 2.注册MVC路由
            var routes = RouteTable.Routes;
            routes.MapRoute(
                name: "Default",
                url: "{controller}/{action}/{id}",
                defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional }
            );
            #endregion
        }

3.带参数的控制器构造函数

    public class HomeController : Controller
    {
        public HomeController(Say say)
        {

        }
        public string Index()
        {
            return "Hello World";
        }
    }

    public class Say
    {
        public string Get()
        {
            return "Hello World";
        }
    }

4.浏览器访问~/

结合ASP.NET Web API

1.Install-Package Autofac.WebApi

2.由于WebAPI需要,引用系统自带Web.Http和Web.Http.WebHost

3.Application_Start添加此方法

        protected void Application_Start(object sender, EventArgs e)
        {
            var configuration = GlobalConfiguration.Configuration;
            #region Autofac WebAPI注入
            var builder = new ContainerBuilder();
            builder.RegisterApiControllers(Assembly.GetExecutingAssembly());
            builder.RegisterAssemblyTypes(Assembly.GetExecutingAssembly()).AsImplementedInterfaces().AsSelf();
            var container = builder.Build();
            configuration.DependencyResolver = new AutofacWebApiDependencyResolver(container);
            #endregion

            #region 注册Web API路由
            configuration.Routes.MapHttpRoute(
                     name: "DefaultApi",
                     routeTemplate: "api/{controller}/{id}",
                     defaults: new { id = RouteParameter.Optional });
            #endregion
        }

4.带参数的控制器构造函数

    public class ValuesController : ApiController
    {
        public ValuesController(Say say)
        {

        }
        public string Get()
        {
            return "Hello World";
        }
    }

    public class Say
    {
        public string Get()
        {
            return "Hello World";
        }
    }

5.浏览器访问~/api/values

结合WCF

1.Install-Package Autofac.Wcf

2.Application_Start添加此方法

        protected void Application_Start(object sender, EventArgs e)
        {
            #region WCF Autofac注入
            var builder = new ContainerBuilder();
            builder.RegisterAssemblyTypes(Assembly.GetExecutingAssembly()).AsImplementedInterfaces().AsSelf();
            var container = builder.Build();
            //WCF IOC容器
            AutofacHostFactory.Container = container;
            #endregion
        }

3.新建svc服务

    public class TestService : ITestService
    {
        public TestService(Say say)
        {

        }
        public string DoWork()
        {
            return "Hello World";
        }
    }

    public class Say
    {
        public string Get()
        {
            return "Hello World";
        }
    }

    [ServiceContract]
    public interface ITestService
    {
        [OperationContract]
        string DoWork();
    }

4.svc指令中加一句:

Factory="Autofac.Integration.Wcf.AutofacServiceHostFactory, Autofac.Integration.Wcf"

5.wcftestclient

惭愧,好久没发博客了