Autofac不填充作用筛选器属性 [英] Autofac is not filling action filter property

问题描述

我有在ASP.NET MVC 3应用程序，需要注射到它的一些相关性的动作过滤器。我使用Autofac.Mvc3作为依赖注入。

I have an action filter in an ASP.NET MVC 3 app that needs some dependencies injected into it. I am using Autofac.Mvc3 as the dependency injector.

根据的autofac维基我只是来注册类型的我要注入，调用 RegisterFilterProvider ，并把公共财产对我的行为过滤器，然后过滤器实例中autofac将填补与合适的对象属性。

According to the autofac wiki I just have to register the types that I want to inject, call RegisterFilterProvider, and put a public property on my action filter, and then autofac will fill the property with the right object during filter instantiation.

下面是我的行为过滤器的一部分：

Here is a part of my action filter:

Public Class LogActionAttribute
    Inherits ActionFilterAttribute

    Property tracer As TraceSource

    Public Overrides Sub OnActionExecuting(filterContext As System.Web.Mvc.ActionExecutingContext)
        ...
        tracer.TraceData(...)
        ...
    End Sub
End Class

下面是我的Global.asax的一部分：

Here is a part of my global.asax:

Public Class MvcApplication
    Inherits System.Web.HttpApplication

    Shared Sub RegisterGlobalFilters(ByVal filters As GlobalFilterCollection)
        filters.Add(New MyHandleErrorAttribute)
        filters.Add(New LogActionAttribute)
    End Sub

    Sub Application_Start()
        InitSettingRepoEtc()
        ...
    End Sub

    Protected Shared Sub InitSettingRepoEtc()
        ...
        Dim builder = New ContainerBuilder
        builder.RegisterControllers(Reflection.Assembly.GetExecutingAssembly)
        ...
        builder.Register(Of TraceSource)(
            Function(x) New TraceSource("requests", SourceLevels.All)).InstancePerHttpRequest()
        ...
        builder.RegisterFilterProvider()
        Dim container = builder.Build
        DependencyResolver.SetResolver(New AutofacDependencyResolver(container))
        ...
    End Sub
End Class

我已经把断点右后 SetResolver ，并在尝试直接窗口：

DependencyResolver.Current.GetService(Of TraceSource)

和我顺利地拿到了从autofac一个TraceSource对象，所以注册似乎是确定。

And I successfully got a TraceSource object from autofac, so the registration seems to be OK.

但在 OnActionExecuting 我的示踪剂属性为空。

我错过了什么？

推荐答案

IIRC提供者不具有全球性过滤器工作。

IIRC the provider doesn't work with 'global' filters.

删除这个功能：

Shared Sub RegisterGlobalFilters(ByVal filters As GlobalFilterCollection)
    filters.Add(New MyHandleErrorAttribute)
    filters.Add(New LogActionAttribute)
End Sub

和代替，注册Autofac直接全局过滤器：

And instead, register the global filters with Autofac directly:

 builder.Register(Of MyHandleErrorAttribute)
     .As(Of IActionFilter)
     .PropertiesAutowired()
     .SingleInstance();

 builder.Register(Of LogActionAttribute)
     .As(Of IActionFilter)
     .PropertiesAutowired()
     .SingleInstance();

Autofac将创建过滤器，并适当囊括其中。这种方法的好处是，你可以重构使过滤器不是属性衍生，然后用构造函数，而不是财产注入。

Autofac will create the filters and include them appropriately. The advantage of this approach is that you can refactor so the filters are not attribute-derived, and then use constructor rather than property injection.

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