MVC 使用IOC实现

实现步骤：

1. 实现IDependencyResolver接口并通过DependencyResolver.SetResolver告知MVC，将部分类型实例解析工作交由IoC容器来处理；

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using Microsoft.Practices.Unity;

namespace MvcIocDemo.IoC
{
    public class UnityDependencyResolver : IDependencyResolver
    {
        IUnityContainer container;

        public UnityDependencyResolver(IUnityContainer container)
        {
            this.container = container;
        }

        public object GetService(Type serviceType)
        {
            if (!this.container.IsRegistered(serviceType))
            {
                return null;
            }
            return container.Resolve(serviceType);
        }

        public IEnumerable<object> GetServices(Type serviceType)
        {
            return container.ResolveAll(serviceType);
        }
    }
}

2. 继承DefaultControllerFactory，重载GetControllerInstance方法，并通过IoC容器将之注册为IControllerFactory的实现。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using System.Web.Routing;
using Microsoft.Practices.Unity;
using System.Web.SessionState;

namespace MvcIocDemo.IoC
{
    public class UnityControllerFactory : DefaultControllerFactory
    {
        IUnityContainer container;
        public UnityControllerFactory(IUnityContainer container)
        {
            this.container = container;
        }

        protected override IController GetControllerInstance(RequestContext reqContext,
            Type controllerType)
        {
            return container.Resolve(controllerType) as IController;
        }

    }

}

3  在函数Application_Start() 中添加如下代码：

        protected void Application_Start()
        {
            AreaRegistration.RegisterAllAreas();

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

            IUnityContainer container = new UnityContainer();
            container.RegisterType<IServiceA, ServiceA>();
            container.RegisterType<IServiceB, ServiceB>();;
            container.RegisterType<IControllerFactory, UnityControllerFactory>();
            DependencyResolver.SetResolver(new UnityDependencyResolver(container));
        }

4　在控制器中使用

    public class HomeController : Controller
    {
        protected IServiceA _serviceA;
        protected IServiceB _serviceB;

        public HomeController(IServiceA serviceA, IServiceB serviceB)
        {
            _serviceA = serviceA;
            _serviceB = serviceB;
        }

        public ActionResult Index()
        {
            ViewBag.A = _serviceA.Say();
            ViewBag.B = _serviceB.Write();
            return View();
        }

    }