【发布时间】：2014-12-06 09:06:26
【问题描述】：
我正在使用 C#、.NET Framework 4.5.1 开发 ASP.NET Web Api 2.2。
将我的 Web.Api 更新到 Ninject 3.2.0 后，我收到此错误：
Error activating ModelValidatorProvider using binding from ModelValidatorProvider to NinjectDefaultModelValidatorProvider
A cyclical dependency was detected between the constructors of two services.
Activation path:
3) Injection of dependency ModelValidatorProvider into parameter defaultModelValidatorProviders of constructor of type DefaultModelValidatorProviders
2) Injection of dependency DefaultModelValidatorProviders into parameter defaultModelValidatorProviders of constructor of type NinjectDefaultModelValidatorProvider
1) Request for ModelValidatorProvider
Suggestions:
1) Ensure that you have not declared a dependency for ModelValidatorProvider on any implementations of the service.
2) Consider combining the services into a single one to remove the cycle.
3) Use property injection instead of constructor injection, and implement IInitializable
if you need initialization logic to be run after property values have been injected.
我在NinjectWebCommon 中得到了异常：
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)
{
var containerConfigurator = new NinjectConfigurator();
containerConfigurator.Configure(kernel);
}
}
NinjectDependencyResolver类：
using Ninject;
using System;
using System.Collections.Generic;
using System.Web.Http.Dependencies;
namespace Matt.SocialNetwork.Web.Common
{
public class NinjectDependencyResolver : IDependencyResolver
{
private readonly IKernel _container;
public IKernel Container
{
get { return _container; }
}
public NinjectDependencyResolver(IKernel container)
{
_container = container;
}
public object GetService(Type serviceType)
{
return _container.TryGet(serviceType);
}
public IEnumerable<object> GetServices(Type serviceType)
{
return _container.GetAll(serviceType);
}
public IDependencyScope BeginScope()
{
return this;
}
public void Dispose()
{
// noop
}
}
}
NinjectConfigurator类：
public class NinjectConfigurator
{
public void Configure(IKernel container)
{
// Add all bindings/dependencies
AddBindings(container);
// Use the container and our NinjectDependencyResolver as
// application's resolver
var resolver = new NinjectDependencyResolver(container);
GlobalConfiguration.Configuration.DependencyResolver = resolver;
}
// Omitted for brevity.
}
奇怪的是它可以完美地编译和运行，但是更新后它就不起作用了。
我已经更改了这个public class NinjectDependencyResolver : IDependencyResolver, System.Web.Mvc.IDependencyResolver，但它仍然不起作用。
有什么想法吗？
更新
调试中看到NinjectDependencyResolver这里抛出了异常：
public IEnumerable<object> GetServices(Type serviceType)
{
return _container.GetAll(serviceType);
}
它运行两次。第一次serviceType 是IFilterProvider，第二次serviceType 是ModelValidatorProvider，然后我得到了异常。
这些是我正在使用的 Ninject 包：
<package id="Ninject" version="3.2.2.0" targetFramework="net451" />
<package id="Ninject.MVC5" version="3.2.1.0" targetFramework="net45" />
<package id="Ninject.Web.Common" version="3.2.3.0" targetFramework="net451" />
<package id="Ninject.Web.Common.WebHost" version="3.2.3.0" targetFramework="net451" />
<package id="Ninject.Web.WebApi" version="3.2.2.0" targetFramework="net451" />
这些程序集的先前版本是：
<package id="Ninject" version="3.2.2.0" targetFramework="net45" />
<package id="Ninject.MVC5" version="3.2.1.0" targetFramework="net45" />
<package id="Ninject.Web.Common" version="3.2.2.0" targetFramework="net451" />
<package id="Ninject.Web.Common.WebHost" version="3.2.0.0" targetFramework="net45" />
<package id="Ninject.Web.WebApi" version="3.2.0.0" targetFramework="net451" />
第二次更新
我发现问题出在这个类上：
public static class WebContainerManager
{
public static IKernel GetContainer()
{
var resolver = GlobalConfiguration.Configuration.DependencyResolver as NinjectDependencyResolver;
if (resolver != null)
{
return resolver.Container;
}
throw new InvalidOperationException("NinjectDependencyResolver not being used as the MVC dependency resolver");
}
public static T Get<T>()
{
return GetContainer().Get<T>();
}
}
我在这里设置Dependency Resolver：
public class NinjectConfigurator
{
/// <summary>
/// Entry method used by caller to configure the given
/// container with all of this application's
/// dependencies. Also configures the container as this
/// application's dependency resolver.
/// </summary>
public void Configure(IKernel container)
{
// Add all bindings/dependencies
AddBindings(container);
// Use the container and our NinjectDependencyResolver as
// application's resolver
var resolver = new NinjectDependencyResolver(container);
GlobalConfiguration.Configuration.DependencyResolver = resolver;
}
我在一个继承自ExceptionFilterAttribute的类中使用WebContainerManager：
public class UnhandledExceptionFilter : ExceptionFilterAttribute
{
private readonly IExceptionLogHelper excepLogHelper;
public UnhandledExceptionFilter()
: this(WebContainerManager.Get<IExceptionLogHelper>()) {}
public UnhandledExceptionFilter(IExceptionLogHelper exceptionLogHelper)
{
this.excepLogHelper = exceptionLogHelper;
}
public override void OnException(HttpActionExecutedContext actionExecutedContext)
{
this.excepLogHelper.LogException(actionExecutedContext);
}
}
所以，如果我删除 WebContainerManager，我不会得到那个循环。
【问题讨论】：
-
你试过卸载所有的ninject包并重新安装吗？确保您确实获得了最新版本？
-
是的，我这样做了，我得到了同样的错误。
-
你能把mcve作为视觉工作室项目上传到gist/github repo或类似的东西上吗？我想试一试。
-
作为旁注，我不会使用
WebContainerManager静态捕获内核并用作服务定位器，而是使用this approach，它支持将ctor-injection 注入IActionFilter。另见here
标签： c# ninject ninject.web.mvc