使用Castle Windsor子容器来解析具有特定实例的类型 [英] Using Castle Windsor child containers to resolve a type with a specific instance

问题描述

我目前正在使用Castle Windsor的子容器功能在工厂方法中使用特定实例覆盖特定类型的注册。我纯粹是在使用子容器，因此对于单个解决方案来说注册是临时的-换句话说，我不希望该注册影响该类型的所有决议。

I'm currently using Castle Windsor's child container functionality to override the registration of a particular type with a specific instance in a factory method. I am using the child containers purely so that the registration is temporary for a single resolution - in other words, I don't want the registration to affect all resolutions for that type.

也许有些代码可以解释我的意思。

Perhaps some code will explain what I mean.

我有一个Func，它充当工厂 Func< IReportCategory，IReportCategoryViewModel> -我为它提供了一个IReportCategory的实现，它返回了一个IReportCategoryViewModel的新实例。 （IReportCategoryViewModel依赖于IReportCategory。）

I have a Func which acts as a factory Func<IReportCategory, IReportCategoryViewModel> - I give it an implementation of an IReportCategory and it returns a new instance of an IReportCategoryViewModel. (IReportCategoryViewModel has a dependency on IReportCategory).

这已在温莎城堡注册，如下所示：

This is registered with Castle Windsor as follows:

        container.Register(
            Component.For<Func<IReportCategory, IReportCategoryViewModel>>().Instance(
                category => ResolveCategoryViewModelFactory(container, category)));

ResolveCategoryViewModelFactory 的实现方式如下：

    private CategoryViewModel ResolveCategoryViewModelFactory(IWindsorContainer container, IReportCategory category)
    {
        using (IWindsorContainer childContainer = new WindsorContainer())
        {
            childContainer.Register(Component.For<IReportCategory>().Instance(category));
            container.AddChildContainer(childContainer);

            return childContainer.Resolve<IReportCategoryViewModel>();
        }
    }

以上方法实现的是IReportCategoryViewModel的分辨率，注入IReportCategory的特定实例作为依赖项。如果IReportCategoryViewModel还有其他需要满足的依赖关系，则这些依赖关系将由容器自动注入。

What the above method achieves is the resolution of IReportCategoryViewModel, injecting the specific instance of IReportCategory as a dependency. If IReportCategoryViewModel has other dependencies that need satisfying, then these get automatically injected by the container.

我随后可以按如下方式使用Func：

I can subsequently use the Func as follows:

public class Test
{
    private readonly Func<IReportCategory, IReportCategoryViewModel> factory;

    public Test(Func<IReportCategory, IReportCategoryViewModel> factory)
    {
        this.factory = factory;
    }

    public void ResolveTest()
    {
        // Create a category (note: this would probably be resolved from the container in some way)
        IReportCategory category = new ReportCategory();

        // Call into the factory to resolve the view model
        IReportCategoryViewModel vm = factory(category);
    }
    ...

问题：这似乎是一件合适的事情吗？从我得到的印象来看，温莎城堡不推荐使用子容器-还有另一种方法可以达到同样的效果？

Question: Does this seem like a suitable thing to do? From the impression I get, child containers are not recommended in Castle Windsor - is there another way of achieving the same result?

感谢您的帮助。

推荐答案

绝对有更好的方法，而您正在使用的代码现在存在错误-它将尝试释放所有组件实例处置子容器时您正在解决，因此在您有机会使用子容器之前，它们可能不可用（处置）。

Absolutely there are better ways to go, and the code you're using right now has a bug - it will try to release all the component instances you're resolving when you dispose of the child container, therefore they might be unusable (disposed) before you even get a chance to use them.

如果我理解您的解释正确地感觉就像是类型化工厂的工作。

If I understand your explanation correctly it feels like a job for typed factories.

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