Angular2 viewContainerRef.createComponent 正常工作

Question

我使用 viewContainerRef.createComponent 将动态组件加载到根组件中(......)，但实际上它附加了错误的位置，

我的代码:

-----app.compoment.ts-----

export class AppComponent { 
   private viewContainerRef:ViewContainerRef;
   public constructor(viewContainerRef:ViewContainerRef) {
    this.viewContainerRef = viewContainerRef;
  }
}

-----a.service.ts------

@Injectable()
export class ModalService {
  private viewContainerRef:ViewContainerRef;
    constructor(applicationRef: ApplicationRef, injector: Injector,private compiler: ComponentResolver) { 
        var classOfRootComponent = applicationRef.componentTypes[0];
        // this is an instance of application bootstrap component
        var appInstance = injector.get(classOfRootComponent);
        this.viewContainerRef= appInstance.viewContainerRef;
    }
    alert() {console.log(this.viewContainerRef);
        this.compiler.resolveComponent(ModalComponent)
        .then(
            (factory) =>
            this.viewContainerRef.createComponent(factory, 0, this.viewContainerRef.injector)
        ).then((componentRef) => {
                return componentRef;
            }
        );
    }
}

Answer 1

这是“按设计”的。另请参阅此讨论 https://github.com/angular/angular/issues/9035

如果你想要<custom-modal>插入内部 <my-app>将目标元素添加到 <my-app> 的模板中并将其用作目标。

您需要从 AppComponent 传递它到 ModalService喜欢

@Component({
  selector: 'my-app',
  template: `<div #target></div>`
})
export class AppComponent {
  @ViewChild('target', {read: ViewContainerRef}) viewContainerRef:ViewContainerRef;

  constructor(private modalService:ModalService) {}

  ngAfterViewInit() {
    this.modalService.viewContainerRef = this.viewContainerRef;
  }
}

此 PR 是关于一个类似的用例，您可能会感兴趣 https://github.com/angular/angular/pull/9393