相关疑难解决方法(0)

我正在尝试将父组件注入子组件.我认为这很简单 - 只需在子代中指定/注入父组件constructor():

constructor(private _parent:AppComponent) {}   // child component constructor

我收到以下错误:

EXCEPTION:无法解析ChildComponent(？)的所有参数.确保它们都具有有效的类型或注释.

我错过了什么？

ChildComponent:

import {Component} from 'angular2/core';
import {AppComponent} from './app.component';

@Component({
  selector: 'child',
  template: `<p>child</p>`
})
export class ChildComponent {
  constructor(private _parent:AppComponent) {}
}

AppComponent:

import {Component} from 'angular2/core';
import {ChildComponent} from './child.component';

@Component({
  selector: 'my-app',
  template: `{{title}} <child></child>
  `,
  directives: [ChildComponent]
})
export class AppComponent {
  title = "Angular 2 - inject parent";
  constructor() { console.clear(); }
}

Plunker