5

我Ninject在 MVC 3 应用程序中使用扩展 EventBroker 和 DependencyCreation。我已经安装并正在使用 Ninject.MVC3 包，因此OnePerRequestModule.

我正在尝试将服务注入IParentService到控制器中。IParentService依赖于ChildService通过 DependencyCreation 扩展创建的（无硬引用）。

这两个服务都在本地事件代理实例（本地到ParentService）上注册。

我希望按请求确定范围，IParentService并且希望依赖项和事件代理与. 我究竟做错了什么？IParentServiceScopeDisposedException

一些代码：

服务定义：

public interface IParentService
{
}

public class ParentService : IParentService
{
    [EventPublication("topic://ParentService/MyEvent")]
    public event EventHandler<EventArgs> MyEvent;
}

public class ChildService
{
    [EventSubscription("topic://ParentService/MyEvent", typeof(bbv.Common.EventBroker.Handlers.Publisher))]
    public void OnMyEvent(object sender, EventArgs eventArgs)
    {            
    }
}

内核注册 (NinjectWebCommon)

    private static void RegisterServices(IKernel kernel)
    {
        kernel.Bind<IParentService>().To<ParentService>()
            .InRequestScope()
            .OwnsEventBroker("ParentServiceBroker")
            .RegisterOnEventBroker("ParentServiceBroker");

        kernel.DefineDependency<IParentService, ChildService>();
        kernel.Bind<ChildService>().ToSelf()
            .WhenInjectedInto<ParentService>()
            .InDependencyCreatorScope()
            .RegisterOnEventBroker("ParentServiceBroker");            
    }

堆栈跟踪：

[ScopeDisposedException: The requested scope has already been disposed.]
   Ninject.Extensions.NamedScope.NamedScopeExtensionMethods.GetScope(IContext context, String scopeParameterName) in c:\Projects\Ninject\ninject.extensions.namedscope\src\Ninject.Extensions.NamedScope\NamedScopeExtensionMethods.cs:118
   Ninject.Extensions.NamedScope.NamedScopeExtensionMethods.GetScope(IContext context, String scopeParameterName) in c:\Projects\Ninject\ninject.extensions.namedscope\src\Ninject.Extensions.NamedScope\NamedScopeExtensionMethods.cs:126
   Ninject.Extensions.NamedScope.<>c__DisplayClass1`1.<InNamedScope>b__0(IContext context) in c:\Projects\Ninject\ninject.extensions.namedscope\src\Ninject.Extensions.NamedScope\NamedScopeExtensionMethods.cs:40
   Ninject.Planning.Bindings.BindingConfiguration.GetScope(IContext context) in c:\Projects\Ninject\ninject\src\Ninject\Planning\Bindings\BindingConfiguration.cs:119
   Ninject.Planning.Bindings.Binding.GetScope(IContext context) in c:\Projects\Ninject\ninject\src\Ninject\Planning\Bindings\Binding.cs:224
   Ninject.Activation.Context.GetScope() in c:\Projects\Ninject\ninject\src\Ninject\Activation\Context.cs:123
   Ninject.Activation.Caching.Cache.TryGet(IContext context) in c:\Projects\Ninject\ninject\src\Ninject\Activation\Caching\Cache.cs:110
   Ninject.Activation.Context.Resolve() in c:\Projects\Ninject\ninject\src\Ninject\Activation\Context.cs:150
   Ninject.<>c__DisplayClass10.<Resolve>b__c(IBinding binding) in c:\Projects\Ninject\ninject\src\Ninject\KernelBase.cs:386
   System.Linq.WhereSelectEnumerableIterator`2.MoveNext() +145
   System.Linq.<CastIterator>d__b1`1.MoveNext() +85
   System.Linq.Enumerable.Single(IEnumerable`1 source) +191
   Ninject.ResolutionExtensions.Get(IResolutionRoot root, String name, IParameter[] parameters) in c:\Projects\Ninject\ninject\src\Ninject\Syntax\ResolutionExtensions.cs:50
   Ninject.Extensions.ContextPreservation.ContextPreservationExtensionMethods.ContextPreservingGet(IContext context, String name, IParameter[] parameters) in c:\Projects\Ninject\ninject.extensions.contextpreservation\src\Ninject.Extensions.ContextPreservation\ContextPreservationExtensionMethods.cs:56
   Ninject.Extensions.bbvEventBroker.<>c__DisplayClass2`1.<RegisterOnEventBroker>b__0(IContext ctx, T instance) in c:\Projects\Ninject\ninject.extensions.bbveventbroker\src\Ninject.Extensions.bbvEventBroker\EventBrokerExtensionMethods.cs:45
   Ninject.Planning.Bindings.<>c__DisplayClass29`1.<OnDeactivation>b__28(IContext context, Object instance) in c:\Projects\Ninject\ninject\src\Ninject\Planning\Bindings\BindingConfigurationBuilder.cs:513
   Ninject.Activation.Strategies.<>c__DisplayClass4.<Deactivate>b__3(Action`2 action) in c:\Projects\Ninject\ninject\src\Ninject\Activation\Strategies\BindingActionStrategy.cs:42
   Ninject.Infrastructure.Language.ExtensionsForIEnumerableOfT.Map(IEnumerable`1 series, Action`1 action) in c:\Projects\Ninject\ninject\src\Ninject\Infrastructure\Language\ExtensionsForIEnumerableOfT.cs:32
   Ninject.Activation.Strategies.BindingActionStrategy.Deactivate(IContext context, InstanceReference reference) in c:\Projects\Ninject\ninject\src\Ninject\Activation\Strategies\BindingActionStrategy.cs:42
   Ninject.Activation.<>c__DisplayClass6.<Deactivate>b__4(IActivationStrategy s) in c:\Projects\Ninject\ninject\src\Ninject\Activation\Pipeline.cs:72
   Ninject.Infrastructure.Language.ExtensionsForIEnumerableOfT.Map(IEnumerable`1 series, Action`1 action) in c:\Projects\Ninject\ninject\src\Ninject\Infrastructure\Language\ExtensionsForIEnumerableOfT.cs:32
   Ninject.Activation.Pipeline.Deactivate(IContext context, InstanceReference reference) in c:\Projects\Ninject\ninject\src\Ninject\Activation\Pipeline.cs:72
   Ninject.Activation.Caching.Cache.Forget(CacheEntry entry) in c:\Projects\Ninject\ninject\src\Ninject\Activation\Caching\Cache.cs:253
   Ninject.Activation.Caching.Cache.Forget(IEnumerable`1 cacheEntries) in c:\Projects\Ninject\ninject\src\Ninject\Activation\Caching\Cache.cs:242
   Ninject.Activation.Caching.Cache.Clear(Object scope) in c:\Projects\Ninject\ninject\src\Ninject\Activation\Caching\Cache.cs:197
   Ninject.Web.Common.<>c__DisplayClass2.<DeactivateInstancesForCurrentHttpRequest>b__1(IKernel kernel) in c:\Projects\Ninject\Ninject.Web.Common\src\Ninject.Web.Common\OnePerRequestHttpModule.cs:74
   Ninject.GlobalKernelRegistration.MapKernels(Action`1 action) in c:\Projects\Ninject\ninject\src\Ninject\GlobalKernelRegistration.cs:75
   Ninject.Web.Common.OnePerRequestHttpModule.DeactivateInstancesForCurrentHttpRequest() in c:\Projects\Ninject\Ninject.Web.Common\src\Ninject.Web.Common\OnePerRequestHttpModule.cs:74
   Ninject.Web.Common.OnePerRequestHttpModule.<Init>b__0(Object o, EventArgs e) in c:\Projects\Ninject\Ninject.Web.Common\src\Ninject.Web.Common\OnePerRequestHttpModule.cs:56
   System.Web.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +136
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +69

编辑 - 更多细节

该错误在调用中设置的停用委托中引发RegisterOnEventBroker，其中代码尝试取消注册在事件代理上注册的任何对象。它失败是因为事件代理范围已被释放，大概是因为父服务已被释放。据我所知，Ninject 只会为具有 Transient 范围以外的生命周期的对象调用 OnDeactivation 委托，所以为什么在注册父服务时这不起作用让RequestScope我感到困惑。瞬态范围对于父服务来说是不够的，因为我正因为这个问题而遇到内存泄漏。

我开始怀疑这是否是 EventBroker 扩展中的错误。

4

2 回答 2

2

您必须先绑定然后使用具体类型的自绑定IParentService来定义对象范围和事件代理。ParentServicekernel.Bind<ParentService>().ToSelf()

    private static void RegisterServices(IKernel kernel)
    {
        kernel.Bind<IParentService>().To<ParentService>();


        kernel.Bind<ParentService>().ToSelf()
       .InRequestScope()
       .OwnsEventBroker("ParentServiceBroker")
       .RegisterOnEventBroker("ParentServiceBroker");

        kernel.DefineDependency<IParentService, ChildService>();
        kernel.Bind<ChildService>().ToSelf()
            .WhenInjectedInto<ParentService>()
            .InDependencyCreatorScope()
            .RegisterOnEventBroker("ParentServiceBroker"); 
    }

编辑： 如果您要解析的类型是具体类型（如上面的 ParentService ），Ninject 将通过称为隐式自绑定的机制自动创建默认关联。像这样：

 kernel.Bind<ParentService>().ToSelf();

另一方面，隐式自绑定是在默认的对象作用域中生成的，即Transient. 这就是为什么您的代码不在Request范围内运行的原因。

有关更多信息，请参见此处

编辑2：

bbvEventBroker范围扩展中存在一个错误Request，导致 EventBroker 在处置在该 EventBroker 上注册的对象之前被处置。因此，OnDeactivation在对象的方法中没有 EventBroker 可以调用它的 Unregister 并ScopeDisposedException抛出它。

    public static IBindingOnSyntax<T> OwnsEventBroker<T>(this IBindingOnSyntax<T> syntax, string eventBrokerName)
    {
        string namedScopeName = "EventBrokerScope" + eventBrokerName;
        syntax.DefinesNamedScope(namedScopeName);
        syntax.Kernel.Bind<IEventBroker>().To<EventBroker>().InNamedScope(namedScopeName).Named(eventBrokerName);
        syntax.Kernel.Bind<IEventBroker>().ToMethod(ctx => ctx.ContextPreservingGet<IEventBroker>(eventBrokerName)).WhenTargetNamed(eventBrokerName);
        return syntax;
    }

您可以在OwnsEventBroker方法 NamedScope 中看到在对象 ( ParentService) 的范围内定义，它强制它在对象 ( ) 之前处置ParentService。

另一方面，OnDeactivation在对象 ( ParentService) 中，需要较早处理的 EventBroker。

    public static IBindingOnSyntax<T> RegisterOnEventBroker<T>(
        this IBindingOnSyntax<T> syntax, string eventBrokerName)
    {
        return
            syntax.OnActivation((ctx, instance) => ctx.ContextPreservingGet<IEventBroker>(eventBrokerName).Register(instance))
                  .OnDeactivation((ctx, instance) => ctx.ContextPreservingGet<IEventBroker>(eventBrokerName).Unregister(instance));
    }

EventBrokerExtensionMethods.cs

解决方案是使用创建对象树NamedScope。在Request范围内定义父级，同时NamedScope为其子级（发布者/订阅者）定义 a 并拥有事件代理（OwnsEventBroker）。然后在父级定义的命名范围内定义一个 Publisher( ChildService1) 和一个 Subscriber( ChildService2)。通过这种方式，您可以确保事件代理的所有者将在他们的孩子之后被处置。

于 2013-05-08T15:08:25.350 回答
2

Ninject 核心当前在停用对象本身之前停用对象范围内的对象。

更改顺序似乎可以解决该问题。尽管在推动该更改之前，我必须检查这可能对其他情况产生什么副作用。

于 2013-05-11T11:19:11.323 回答