MVC 和 Web API 控制器的简单注入器初始化

Question

我有一个 Web API 控制器，其中包含一些 DI 资源。出于以后的需要，我添加了一个 MVC 控制器，现在我也需要相同的资源 DI。这是我原来的配置：

    [assembly: WebActivator.PostApplicationStartMethod(typeof(CineplexSearch.App_Start.SimpleInjectorWebApiInitializer), "Initialize")]

namespace CineplexSearch.App_Start
{
    using System.Web.Http;
    using SimpleInjector;
    using SimpleInjector.Integration.WebApi;

    public static class SimpleInjectorWebApiInitializer
    {
        /// <summary>Initialize the container and register it as Web API Dependency Resolver.</summary>
        public static void Initialize()
        {
            var container = new Container();
            container.Options.DefaultScopedLifestyle = new WebApiRequestLifestyle();

            InitializeContainer(container);

            container.RegisterWebApiControllers(GlobalConfiguration.Configuration);

            container.Verify();

            GlobalConfiguration.Configuration.DependencyResolver =
                new SimpleInjectorWebApiDependencyResolver(container);
        }

        private static void InitializeContainer(Container container)
        {
            container.Register<ICachingManager, CachingManager>(Lifestyle.Transient);
            container.Register<IDataAccessLayer, DataAccessLayer>(Lifestyle.Transient);
        }
    }
}

我也可以在同一个地方为 MVC 控制器注册 DI 吗？我可以重复使用容器吗？

更新：我必须关闭，但现在我在 Web API 控制器中收到错误，我需要一个无参数构造函数；我尝试添加它，但当然没有注入任何东西

public static class SimpleInjectorWebApiInitializer
{
    /// <summary>Initialize the container and register it as Web API Dependency Resolver.</summary>
    public static void Initialize()
    {
        var container = new Container();
        container.Options.DefaultScopedLifestyle = new WebRequestLifestyle();

        InitializeContainer(container);

        container.RegisterWebApiControllers(GlobalConfiguration.Configuration);
        container.RegisterMvcControllers(Assembly.GetExecutingAssembly());

        container.Verify();

        //GlobalConfiguration.Configuration.DependencyResolver = new SimpleInjectorWebApiDependencyResolver(container);
        DependencyResolver.SetResolver(new SimpleInjectorDependencyResolver(container));
    }

    private static void InitializeContainer(Container container)
    {
        container.Register<ICachingManager, CachingManager>(Lifestyle.Transient);
        container.Register<IDataAccessLayer, DataAccessLayer>(Lifestyle.Transient);
    }
}

Answer 1

我可以重复使用容器吗？

是的，你可以，你应该这样做。每个应用程序域通常应该有一个容器实例。

Simple Injector 文档的MVC integration documentation 解释说，您应该如下设置MVC DependencyResolver：

DependencyResolver.SetResolver(new SimpleInjectorDependencyResolver(container));

不过，为了方便起见，您应该将WebRequestLifestyle 注册为DefaultScopedLifestyle：

container.Options.DefaultScopedLifestyle = new WebRequestLifestyle();

这也适用于 Web API，因为您只在 IIS 中运行 Web API。

所以你需要同时配置 DependencyResolver。

Answer 2

我想加两分钱，因为在阅读了史蒂文的答案和它下面的 cmets 之后，我仍然遇到了一些错误。最终这与配置的顺序有关。

protected void Application_Start()
{
    //set the default scoped lifestyle
    Container container = new Container();
    container.Options.DefaultScopedLifestyle = new WebRequestLifestyle();

    ...
    //do class registration here. I did it with Scoped lifestyle
    ...
    //Let the SimpleInjector.Intergration packages register the controllers.       
    container.RegisterWebApiControllers(GlobalConfiguration.Configuration);
    container.RegisterMvcControllers(Assembly.GetExecutingAssembly());

    AreaRegistration.RegisterAllAreas();
    //This must be here because we first need to do above before registering the web api. See WebApiConfig code.
    GlobalConfiguration.Configure(WebApiConfig.Register);
    FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
    RouteConfig.RegisterRoutes(RouteTable.Routes);
    BundleConfig.RegisterBundles(BundleTable.Bundles);

    //don't set the resolver here, do it in WebApiConfig.Register()
    //DependencyResolver.SetResolver(new SimpleInjectorWebApiDependencyResolver(container));
    DependencyResolver.SetResolver(new SimpleInjectorDependencyResolver(container));
    container.Verify(SimpleInjector.VerificationOption.VerifyAndDiagnose);
}

WebApiConfig：

public static class WebApiConfig
{
    public static void Register(HttpConfiguration config)
    {
        // Web API routes
        config.MapHttpAttributeRoutes();
        //set the webApi resolver here!
        config.DependencyResolver = new SimpleInjectorWebApiDependencyResolver(DependencyInjectionCoreSetup._Container);
        //then the rest..
        var route = config.Routes.MapHttpRoute(
        ....
    }
}

Answer 3

还要注意 WebRequestLifestyle() 在当时已经过时。 您可以改用：

//...

container.Options.DefaultScopedLifestyle = new SimpleInjector.Lifestyles.AsyncScopedLifestyle();

//...