装饰者的Angular 2依赖注入 [英] Angular 2 dependency injection for decorators

问题描述

有没有办法将服务依赖项注入到 @Component 装饰中，像这样？

Is there any way to inject a service dependency into a @Component decoration, something like this?

@Component({
    selector: injectedService.getPrefix() + 'my-component'
})
export class MyComponent { }

或者，如果没有，也许可以替代 @Component 并将依赖项注入子类以获得类似的结果？

Or, if not, might it be possible to subsclass @Component and inject a dependency into the subclass to achieve a similar result?

推荐答案

更新> = RC.5 >

@NgModule({
  ...
})
export class AppModule {
  ngDoBootstrap(moduleRef) {
    appInjector(moduleRef.injector);
  }
}

appInjector 实现，请参见下文

原始< = RC.5

Angular2不直接支持此功能。您可以将注入器存储在Angular应用程序外部，然后从那里引用它，如@CanActivate（）装饰器所示的解决方法所示。 /github.com/angular/angular/issues/4112#issuecomment-153811572 rel = nofollow noreferrer> https://github.com/angular/angular/issues/4112#issuecomment-153811572 。
（ 柱塞示例 ）

This is not directly supported by Angular2. You can store the injector outside of your Angular app and then reference it from there like demonstrated as a workaround for the @CanActivate() decorator in https://github.com/angular/angular/issues/4112#issuecomment-153811572. (Plunker example)

在 main.ts 中，将注入器分配给 appInjector

In main.ts the injector is assigned to appInjector

bootstrap(App, [
  Auth,
  HTTP_PROVIDERS,
  ROUTER_PROVIDERS,
  provide(LocationStrategy, {useClass: HashLocationStrategy})
]).then((appRef: ComponentRef) => {
  // store a reference to the application injector
  appInjector(appRef.injector);
});

app-injector.ts

let appInjectorRef: Injector;
export const appInjector = (injector?: Injector):Injector => {
    if (injector) {
      appInjectorRef = injector;
    }

    return appInjectorRef;
};

然后您可以得到对注入器的引用，例如

then you can get a reference to the injector like

appInjector()...

这赢了如果在 bootstrap（）完成之前创建组件，则无法工作。

This won't work if the component is created before bootstrap() is completed.

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