SimpleInjector正在生成多个实例 [英] SimpleInjector multiple instances being generated
问题描述
I'm面临使用simpleInjector当一个奇怪的行为
下面的代码说明了我的情况:
A类:IA,IB< D> {}
然后,i'm注册它,每interface's例如一次,方法如下:在typeof运算
的foreach(VAR服务(A ).GetInterfaces())
{
container.RegisterSingle(服务的typeof(A));
}
我的目标,就是要能够检索同一个实例(单), A的,无论是使用IA或IB。 IB代表一个EventListener接口。
把一个断点A's构造我可以看到它被称为两次当container.verify( )方法被调用,也就是说,不是在这里有一个单身I'm。
What's不对的情况?我需要的威胁泛型接口以不同的方式?
注册多个接口与同实施
要坚持接口分离原则,它是
重要的保持接口收窄。虽然在大多数情况下实现
实现一个单一的接口,它有时是有益的对一个单一的实施
多个接口。下面是如何注册这个
的例子:
块引用>
//默认地将Impl工具IInterface1,IInterface2和IInterface3。
变种注册=
Lifestyle.Singleton.CreateRegistration<默认地将Impl>(容器);
container.AddRegistration(typeof运算(IInterface1),注册);
container.AddRegistration(typeof运算(IInterface2),注册);
container.AddRegistration(typeof运算(IInterface3),注册);
VAR一个= container.GetInstance< IInterface1>();
变种B = container.GetInstance< IInterface2>();
//由于默认地将Impl是一个单,这两个请求返回相同的实例。
Assert.AreEqual(A,B);
参考:的注册多个接口具有相同的实现
I´m facing a strange behaviour when using simpleInjector.
The following code illustrates my scenario:
class A: IA, IB<D>{}
Then, i´m registering it, once per interface´s instance, as follows:
foreach (var service in typeof(A).GetInterfaces()) { container.RegisterSingle(service, typeof(A)); }
My goal, is to be able to retrieve the same instance (singleton), of A, using either IA or IB. IB stands for a eventlistener interface.
Putting a breakpoint on A´s constructor I can see it being called twice when the container.verify() method is called, meaning that I´m not having a singleton here.
What´s wrong with this scenario? Do I need to threat generics interface in a different fashion?
解决方案Register multiple interfaces with the same implementation
To adhere to the Interface Segregation Principle, it is important to keep interfaces narrow. Although in most situations implementations implement a single interface, it can sometimes be beneficial to have multiple interfaces on a single implementation. Here is an example of how to register this:
// Impl implements IInterface1, IInterface2 and IInterface3. var registration = Lifestyle.Singleton.CreateRegistration<Impl>(container); container.AddRegistration(typeof(IInterface1), registration); container.AddRegistration(typeof(IInterface2), registration); container.AddRegistration(typeof(IInterface3), registration); var a = container.GetInstance<IInterface1>(); var b = container.GetInstance<IInterface2>(); // Since Impl is a singleton, both requests return the same instance. Assert.AreEqual(a, b);
Reference: Register multiple interfaces with the same implementation
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