从 UnityContainer 中检索实例化类型

Question

（使用 Unity 4.0.1）

给定一个 UnityContainer 对象，是否有任何方法可以检索到该时间点之前容器已实例化的所有对象？例如。像

IEnumerable<object> instantiatedObjects = unityContainer.GetAllInstantiatedObjects();

或者，更好的是，根据从给定类型派生的那些进行过滤：

IEnumerable<IFoo> instantiatedFoos = unityContainer.GetAllInstantiatedObjects<IFoo>();

Answer 1

遵循 , the following approach implements a custom Unity extension 策略，在 PostInitializtion 时保持对每个实例化对象的引用。

N.B。以下代码仅供参考，不代表thread-safe/exception-safe等

首先，扩展 class 及其依赖的其他 classes 的实现。

public class ObjectContainer
{
    private readonly List<object> _instantiatedObjects = new List<object>();
    public void Add(object instantiatedObject)
    {
        _instantiatedObjects.Add(instantiatedObject);
    }
    public IEnumerable<object> GetInstantiatedObjects()
    {
        return _instantiatedObjects;
    }
    public IEnumerable<T> GetInstantiatedObjects<T>()
    {
        return GetInstantiatedObjects().OfType<T>();
    }
}

public class InstantiatedObjectsStrategy : BuilderStrategy
{
    private readonly ObjectContainer _objectContainer;
    public InstantiatedObjectsStrategy(ObjectContainer objectContainer)
    {
        _objectContainer = objectContainer;
    }
    public override void PostBuildUp(IBuilderContext context)
    {
        _objectContainer.Add(context.Existing);
    }
}

public class InstantiatedObjectsExtension : UnityContainerExtension
{
    private readonly ObjectContainer _objectContainer = new ObjectContainer();
    protected override void Initialize()
    {
        Context.Container.RegisterInstance(_objectContainer);
        Context.Strategies.Add(new InstantiatedObjectsStrategy(_objectContainer),
            UnityBuildStage.PostInitialization);
    }
}

扩展可以在创建后立即添加到 UnityContainer 中：

IUnityContainer container = new UnityContainer();
container.AddNewExtension<InstantiatedObjectsExtension>();

然后可以在稍后阶段从容器中检索实例化对象，如下所示：

IEnumerable<object> instantiatedObjects = container.Resolve<ObjectContainer>().GetInstantiatedObjects();
IEnumerable<Foo> instantiatedFoos = container.Resolve<ObjectContainer>().GetInstantiatedObjects<Foo>();

从 UnityContainer 中检索实例化类型

Retrieve instantiated types from UnityContainer

c#

unity-container