根据决心定制城堡生活方式

Question

对于 Castle Windsor，假设我有以下类：

public class LowLevelComponent
{
}

public class HighLevelComponent
{
    readonly LowLevelComponent LowLevelComponent;

    public HighLevelComponent(LowLevelComponent lowLevelComponent)
    {
        LowLevelComponent = lowLevelComponent;
    }
}

public class ComponentBeingResolved
{
    readonly LowLevelComponent LowLevelComponent;
    readonly HighLevelComponent HighLevelComponent;

    public ComponentBeingResolved(LowLevelComponent lowLevelComponent,
                                  HighLevelComponent highLevelComponent)
    {
        LowLevelComponent = lowLevelComponent;
        HighLevelComponent = highLevelComponent;
    }
}

以最简单的方式注册：

container.Register(Component.For<LowLevelComponent>());
container.Register(Component.For<HighLevelComponent>());
container.Register(Component.For<ComponentBeingResolved>());

每次我都希望在所有依赖项中使用相同的 LowLevelComponent 实例调用Resolve。

因此，在这些调用之后：

var instance1 = container.Resolve<ComponentBeingResolved>();
var instance2 = container.Resolve<ComponentBeingResolved>();

以下断言应该是正确的：

instance1.LowLevelComponent == instance1.HighLevelComponent.LowLevelComponent
instance1.LowLevelComponent != instance2.LowLevelComponent
instance1.HighLevelComponent != instance2.HighLevelComponent

我还将“你做的一切错了，这就是你应该做的”作为回答 ：-）

Answer 1

您一定听说过人们建议只为您的应用入口点（Main、Controller 等）调用 Resolve 一次。 Castle 文档对此有很好的指南。

Answer 2

根据 Mauricio 的链接，我使用工厂让它工作：

public interface IComponentFactory
{
    T Get<T>();
}

var container = new WindsorContainer();
container.AddFacility<TypedFactoryFacility>();
container.Register(Component.For<LowLevelComponent>()
         .LifeStyle.Custom<ContextualLifestyle>());
container.Register(Component.For<HighLevelComponent>()
         .LifeStyle.Custom<ContextualLifestyle>());
container.Register(Component.For<IComponentFactory>().AsFactory());
//Register the "context-root" component in a child container
var subContainer = new WindsorContainer();
subContainer.Register(Component.For<ComponentBeingResolved>()
            .LifeStyle.Transient);
container.AddChildContainer(subContainer);
container.Register(
    Component.For<ComponentBeingResolved>()
        .LifeStyle.Transient
        //Here's the magic
        .UsingFactoryMethod(
            () =>
                {
                    using (new ContainerContext(container))
                        return subContainer.Resolve<ComponentBeingResolved>();
                }));

用法：

var factory = container.Resolve<IComponentFactory>();
var instance1 = factory.Get<ComponentBeingResolved>();
var instance2 = factory.Get<ComponentBeingResolved>();

不确定这是一个好的黑客还是一个丑陋的黑客，但它工作得非常好。