Web API 2 Ninject“尝试创建控制器时发生错误”

Question

加载控制器时出现此错误。

An error occurred when trying to create a controller of type 'MembersController'. Make sure that the controller has a parameterless public constructor.

我已经添加了

System.Web.Http.GlobalConfiguration.Configuration.DependencyResolver = new Ninject.WebApi.DependencyResolver.NinjectDependencyResolver(kernel);

注册绑定后到NinjectWebCommon 类。

并且我已经注册了相关服务。请参阅编辑

 private static void RegisterServices(IKernel kernel)
 {
     kernel.Bind<IMembersService, MembersService>();
     kernel.Bind<MemberContext, MemberContext>();
 }        

这是我添加的 ninject 包 -

  <package id="Ninject" version="3.2.0.0" targetFramework="net451" />
  <package id="Ninject.MVC5" version="3.2.1.0" targetFramework="net451" />
  <package id="Ninject.Web.Common" version="3.2.0.0" targetFramework="net451" />
  <package id="Ninject.Web.Common.WebHost" version="3.2.0.0" targetFramework="net451" />
  <package id="Ninject.Web.WebApi" version="3.2.4.0" targetFramework="net451" />
  <package id="Ninject.WebApi.DependencyResolver" version="0.1.4758.24814" targetFramework="net451" />

我错过了什么？

编辑

感谢我与 Jerrod Horton（下图）的交谈，我意识到我的绑定不正确。

应该是

private static void RegisterServices(IKernel kernel)
{
    kernel.Bind<IMembersService>().To<MembersService>();
    kernel.Bind<MemberContext>().To<MemberContext>();
}

Answer 1

简答：

您需要安装所有这些软件包：

• 忍者
• Ninject.Extensions.Conventions
• Ninject.Web.Common
• Ninject.Web.Mvc
• Ninject.Web.WebApi
• Ninject.Web.WebApi.WebHost

在大多数情况下，缺少其中之一会导致问题。

Answer 2

您的一个依赖项（或依赖项的一个依赖项）未在 IoC 容器中完全注册。当 web api 尝试解析控制器时，如果它没有它需要的每一个依赖项，那么它将失败，如果您的 IoC 容器正在尝试解析 ProductRepository 但 ProductRepository 在其构造函数中需要 ISqlConnectionProvider ，那么您也必须使用您的 IoC 容器注册 ISqlConnectionProvider .

我将从控制器开始。查看所有输入参数。确保每个都在您的 IoC 容器中注册。然后遍历这些类中的每一个，并确保这些类中的任何依赖项也都已注册（依此类推）。

这是我拥有的适用于 Ninject 的代码。此代码存在于 App_Start 文件夹中名为 NinjectWebCommon.cs 的文件中

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

namespace YourProject.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)
        {
        }        
    }
}

packages.config Ninject sn-p

  <package id="Ninject" version="3.2.2.0" targetFramework="net45" />
  <package id="Ninject.Web.Common" version="3.2.3.0" targetFramework="net45" />
  <package id="Ninject.Web.Common.WebHost" version="3.2.3.0" targetFramework="net45" />
  <package id="Ninject.Web.WebApi" version="3.2.4.0" targetFramework="net45" />
  <package id="Ninject.Web.WebApi.WebHost" version="3.2.4.0" targetFramework="net45" />

packages.config web api 和 asp.net sn-p

  <package id="Microsoft.AspNet.Mvc" version="5.2.3" targetFramework="net45" />
  <package id="Microsoft.AspNet.Razor" version="3.2.3" targetFramework="net45" />
  <package id="Microsoft.AspNet.Web.Optimization" version="1.1.3" targetFramework="net45" />
  <package id="Microsoft.AspNet.WebApi" version="5.2.3" targetFramework="net45" />
  <package id="Microsoft.AspNet.WebApi.Client" version="5.2.3" targetFramework="net45" />
  <package id="Microsoft.AspNet.WebApi.Core" version="5.2.3" targetFramework="net45" />
  <package id="Microsoft.AspNet.WebApi.HelpPage" version="5.2.0" targetFramework="net45" />
  <package id="Microsoft.AspNet.WebApi.WebHost" version="5.2.3" targetFramework="net45" />
  <package id="Microsoft.AspNet.WebPages" version="3.2.3" targetFramework="net45" />
  <package id="Microsoft.jQuery.Unobtrusive.Validation" version="3.2.0" targetFramework="net45" />
  <package id="Microsoft.Web.Infrastructure" version="1.0.0.0" targetFramework="net45" />