Angular2:嵌套子组件不起作用

Angular2: Nesting a child component doesn't work

我已经用 angular 2 玩了几天了。我正在尝试将子选择器插入到父模板中。它应该足够简单,但我无法终生让它发挥作用。我收到以下错误:

“未处理的 Promise 拒绝:模板解析错误: 'child' 不是已知元素:"

我哪里错了?谁能帮我摆脱痛苦??

//app.module.ts
@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    BrowserModule,
    ChildModule
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

//app.component.ts
@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  entryComponents: [ChildComponent]
})
export class AppComponent {
  title = 'app works!';
}

  

  <!-- app.component.html -->
    <h1>
      {{title}}
    </h1>
    <child></child>

//child.module.ts
@NgModule({
    declarations:[ChildComponent]
})
export class ChildModule{}

   

 //child.component.ts
    @Component({
        selector:'child',
        templateUrl: './child.component.html'
    })
    export class ChildComponent{
        
    }

   

 <!-- child.component.html -->
    <h1>child</h1>

您必须导出组件:

@NgModule({
    declarations:[ChildComponent],
    exports :[ChildComponent]
})
export class ChildModule{}