注入实现某些接口的所有服务

本文介绍了注入实现某些接口的所有服务的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

简单情况:

我有多个实现通用接口的服务.所有这些服务都在bootstrap方法中注册.

I have multiple Services that implement a common Interface. All those Services are registered within the bootstrap method.

现在我想拥有另一个服务，该服务将注入所有注册的实现公共接口的服务.

Now I'd like to have another Service, which injects all registered Services that implement the common Interface.

即

export interface MyInterface { foo(): void; } export class Service1 implements MyInterface { foo() { console.out("bar"); } } export class Service2 implements MyInterface { foo() { console.out("baz"); } } export class CollectorService { constructor(services:MyInterface[]) { services.forEach(s => s.foo()); } }

有可能吗?

推荐答案

您需要这样注册您的服务提供商:

You need to register your service providers like this:

boostrap(AppComponent, [ provide(MyInterface, { useClass: Service1, multi:true }); provide(MyInterface, { useClass: Service2, multi:true }); ]);

这仅适用于没有接口的类，因为接口在运行时不存在.

This will work only with classes not with interfaces since interfaces don't exist at runtime.

要使其与接口配合使用，您需要对其进行调整:

To make it work with interfaces, you need to adapt it:

bootstrap(AppComponent, [ provide('MyInterface', { useClass: Service1, multi:true }), provide('MyInterface', { useClass: Service2, multi:true }), CollectorService ]);

并以这种方式注入:

@Injectable() export class CollectorService { constructor(@Inject('MyInterface') services:MyInterface[]) { services.forEach(s => s.foo()); } }

有关更多详细信息，请参见此plunkr: plnkr.co/edit/HSqOEN?p =预览.

See this plunkr for more details: plnkr.co/edit/HSqOEN?p=preview.

有关更多详细信息，请参见此链接:

See this link for more details:

• blog. Thoughtram.io/angular2/2015/11/23/multi-providers-in-angular-2.html