Ninject for Web Api 2 在 ASP.NET MVC 中不起作用

Question

我正在开发一个 ASP.NET MVC 应用程序。在我的应用程序中，我需要提供 REST API。所以我将 Web Api 2 添加到我现有的 MVC 应用程序中。在添加 Web API 2 之前，我使用 ninject 进行依赖注入。我是通过 Nuget 包安装的。

整个网站已经开发并运行。但是当我将 Web Api 2 添加到我的项目中时，问题就开始了。 Ninject for MVC 不能与 Web Api 一起使用。所以我安装了 Ninject for Web Api 2。所以我的 NinjectWebCommon 类在我安装后已经改变了。

这是我在 App_Start 文件夹中的 NinjectWebCommon 文件

[assembly: WebActivatorEx.PreApplicationStartMethod(typeof(AyarDirectory.Web.App_Start.NinjectWebCommon), "Start")]
[assembly: WebActivatorEx.ApplicationShutdownMethodAttribute(typeof(AyarDirectory.Web.App_Start.NinjectWebCommon), "Stop")]

namespace AyarDirectory.Web.App_Start
{
    using System;
    using System.Web;

    using Microsoft.Web.Infrastructure.DynamicModuleHelper;

    using Ninject;
    using Ninject.Web.Common;

    public static class NinjectWebCommon 
    {
        private static readonly Bootstrapper bootstrapper = new Bootstrapper();

        /// <summary>
        /// Starts the application
        /// </summary>
        public static void Start() 
        {
            DynamicModuleUtility.RegisterModule(typeof(OnePerRequestHttpModule));
            DynamicModuleUtility.RegisterModule(typeof(NinjectHttpModule));
            bootstrapper.Initialize(CreateKernel);
        }

        /// <summary>
        /// Stops the application.
        /// </summary>
        public static void Stop()
        {
            bootstrapper.ShutDown();
        }

        /// <summary>
        /// Creates the kernel that will manage your application.
        /// </summary>
        /// <returns>The created kernel.</returns>
        private static IKernel CreateKernel()
        {
            var kernel = new StandardKernel();
            try
            {
                kernel.Bind<Func<IKernel>>().ToMethod(ctx => () => new Bootstrapper().Kernel);
                kernel.Bind<IHttpModule>().To<HttpApplicationInitializationHttpModule>();

                RegisterServices(kernel);
                return kernel;
            }
            catch
            {
                kernel.Dispose();
                throw;
            }
        }

        /// <summary>
        /// Load your modules or register your services here!
        /// </summary>
        /// <param name="kernel">The kernel.</param>
        private static void RegisterServices(IKernel kernel)
        {
            System.Web.Mvc.DependencyResolver.SetResolver(new AyarDirectory.Web.Infrastructure.NinjectDependencyResolver(kernel));
        }        
    }
}

在为 web api 2 安装 ninject 后，我​​只更改了那个地方。然后我运行我的应用程序。网站运行良好。网站仍在运行。但是 Web Api 不起作用。

这是我的解析器类

namespace AyarDirectory.Web.Infrastructure
{
    public class NinjectDependencyResolver : IDependencyResolver
    {
        private IKernel kernel;

        public NinjectDependencyResolver(IKernel kernelParam)
        {
            kernel = kernelParam;
            AddBindings();
        }

        public object GetService(Type serviceType)
        {
            return kernel.TryGet(serviceType);
        }

        public IEnumerable<object> GetServices(Type serviceType)
        {
            return kernel.GetAll(serviceType);
        }

        private void AddBindings()
        {
            kernel.Bind<ICategoryRepo>().To<CategoryRepo>();

        }
    }
}

我像这样在 Api Controller 中进行依赖注入：

public class RegionsController : ApiController
    {
        private IRegionRepo regionRepo;

        private RegionsController(IRegionRepo regionParam)
        {
            this.regionRepo = regionParam;
        }
         . . . }

当我访问 api 控制器的操作之一时，它给了我以下错误。

{"Message":"An error has occurred.","ExceptionMessage":"An error occurred when trying to create a controller of type 'RegionsController'. Make sure that the controller has a parameterless public constructor.","ExceptionType":"System.InvalidOperationException","StackTrace":"   at System.Web.Http.Dispatcher.DefaultHttpControllerActivator.Create(HttpRequestMessage request, HttpControllerDescriptor controllerDescriptor, Type controllerType)\r\n   at System.Web.Http.Controllers.HttpControllerDescriptor.CreateController(HttpRequestMessage request)\r\n   at System.Web.Http.Dispatcher.HttpControllerDispatcher.SendAsyncCore(HttpRequestMessage request, CancellationToken cancellationToken)\r\n   at System.Web.Http.Dispatcher.HttpControllerDispatcher.<SendAsync>d__0.MoveNext()","InnerException":{"Message":"An error has occurred.","ExceptionMessage":"Type 'AyarDirectory.Web.Controllers.Api.RegionsController' does not have a default constructor","ExceptionType":"System.ArgumentException","StackTrace":"   at System.Linq.Expressions.Expression.New(Type type)\r\n   at System.Web.Http.Internal.TypeActivator.Create[TBase](Type instanceType)\r\n   at System.Web.Http.Dispatcher.DefaultHttpControllerActivator.GetInstanceOrActivator(HttpRequestMessage request, Type controllerType, Func`1& activator)\r\n   at System.Web.Http.Dispatcher.DefaultHttpControllerActivator.Create(HttpRequestMessage request, HttpControllerDescriptor controllerDescriptor, Type controllerType)"}}

那么，我的代码有什么遗漏或错误？如何将 Ninject 用于 Web Api 2？我正在使用 MVC 5。

Answer 1

只需执行以下 2 个步骤：

1. 来自 Nugget 包管理器：

安装包 Ninject.Web.WebApi

1. 现在编辑 NinjectWebCommon.cs 文件并在 CreateKernel() 方法的末尾和返回内核属性之前添加以下行：

GlobalConfiguration.Configuration.DependencyResolver = new NinjectDependencyResolver(kernel);

返回内核；