如何使用ASP.NET MVC 3 RTM配置依赖项注入

Question

我正在将一个Web应用程序从ASP.NET 3 Preview 1升级到RTM,我对更新的依赖注入方法感到困惑.我正在使用StructureMap,但这与我的问题无关.以前我需要做的就是如下:

x.For<IControllerFactory>().Use<DefaultControllerFactory>();
x.For<IServiceLocator>().Use(MvcServiceLocator.Current);

现在看来我需要提供IControllerActivator,IViewPageActivator和ModelMetadataProvider的实现,因为否则我从StructureMap收到错误,因为MVC尝试使用依赖项解析器来定位它们.从MVC源看,似乎没有公共默认实现.我在设置这些内容时遗漏了什么？当然这些应该按惯例配置？

需要配置什么以及如何使用StructureMap的例子.作为参考,我目前使用以下丑陋的kludge迫使MVC使用其内部默认值:

x.For<IControllerFactory>().Use<DefaultControllerFactory>();
x.For<IDependencyResolver>().Use(() => DependencyResolver.Current);                
x.For<IControllerActivator>().Use(() => null);
x.For<IViewPageActivator>().Use(() => null);
x.For<ModelMetadataProvider>().Use(ModelMetadataProviders.Current);

编辑:为了清楚我有一个工作的依赖性解析器的StructureMap实现 - 问题是为什么MVC抱怨所有这些接口没有在容器中配置.

Answer 1

通过创建依赖性解析器(IDependencyResolver)类,然后在global.asax中注册该类,我能够使StructureMap与ASP.NET MVC3一起工作.我还没有完全测试这段代码.但是,它在两个应用程序中一直没有任何问题.

StructureMapDependencyResolver.cs

using System.Linq;
using System.Web.Mvc;
using StructureMap;

namespace SomeNameSpace
{
    public class StructureMapDependencyResolver : IDependencyResolver
    {
        private readonly IContainer container;

        public StructureMapDependencyResolver(IContainer container)
        {
            this.container = container;
        }

        public object GetService(System.Type serviceType)
        {
            try
            {
                return this.container.GetInstance(serviceType);
            }
            catch
            {
                return null;
            }
        }

        public System.Collections.Generic.IEnumerable<object> GetServices(System.Type serviceType)
        {
            return this.container.GetAllInstances<object>()
                .Where(s => s.GetType() == serviceType);
        }
    }
}

的Global.asax.cs

        public static void RegisterGlobalFilters(GlobalFilterCollection filters)
        {
            filters.Add(new HandleErrorAttribute());
        }

        public static void RegisterRoutes(RouteCollection routes)
        {
            routes.IgnoreRoute("{resource}.axd/{*pathInfo}");

            routes.MapRoute(
                "Default", // Route name
                "{controller}/{action}/{id}", // URL with parameters
                new { controller = "Home", action = "Index", id = UrlParameter.Optional } // Parameter defaults
            );

        }

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

            DependencyResolver.SetResolver(new StructureMapDependencyResolver(InitContainer()));
            RegisterGlobalFilters(GlobalFilters.Filters);            
            RegisterRoutes(RouteTable.Routes);
        }

        private static IContainer InitContainer()
        {
            ObjectFactory.Initialize(x =>
            {
                x.Scan(y =>
                {
                    y.WithDefaultConventions();
                    y.AssembliesFromApplicationBaseDirectory();
                    y.LookForRegistries();
                });
            });

            return ObjectFactory.Container;
        }