跟踪 MEF 容器创建的实例

发布于 2024-09-14 05:56:29 字数 752 浏览 7 评论 0原文

我正在使用 MEF 创建同一导出的多个实例。

我想跟踪我创建的实例，并且正在查询容器或使用重新组合的集合，但我从来没有得到我的实例......

这是代码：

interface IFoo{};
[Export(typeof(IFoo)),PartCreationPolicy(CreationPolicy.NonShared)]
class Foo{};

  class FooTracker{
     CompositionContainer _container; 
     int HowManyValues()
     {
       // this always returns 1 and invokes a constructor
       return _container.GetExportedValue<IFoo>().Count();
     }

     int HowManyExports(){
       // idem
       return _container.GetExports<IFoo>().Count();
     }

     // idem
     [ImportMany(AllowRecomposition=true,AllowRecomposition=true)]
     protected IEnumerable<IFoo> Foos { get; set; }
  }

我想要得到的是已经存在的实例，如果没有则不创建新实例。

谢谢，弗洛里安

原文

I'm using MEF to create several instances of the same export.

I'd like to keep track of the instances I have created, and am either querying the container or using a recomposited collection, but I never get my instances...

Here's the code:

interface IFoo{};
[Export(typeof(IFoo)),PartCreationPolicy(CreationPolicy.NonShared)]
class Foo{};

  class FooTracker{
     CompositionContainer _container; 
     int HowManyValues()
     {
       // this always returns 1 and invokes a constructor
       return _container.GetExportedValue<IFoo>().Count();
     }

     int HowManyExports(){
       // idem
       return _container.GetExports<IFoo>().Count();
     }

     // idem
     [ImportMany(AllowRecomposition=true,AllowRecomposition=true)]
     protected IEnumerable<IFoo> Foos { get; set; }
  }

What I would like is to get is the already existing instances, not create a new one if there aren't any.

Thanks,
Florian

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