javascript - 在 Angular2 中使用动态组件时出现错误 "ERROR TypeError: Cannot read property ' createComponent' of undefined"

Question

我正在尝试在 angular4 中动态添加组件。我检查了其他问题，但我找不到解决方案。我得到了错误

ERROR TypeError: Cannot read property 'createComponent' of undefined

关于动态组件。

adv.component.ts

import { Component, OnInit, AfterContentInit, ViewChild, ViewContainerRef, ComponentFactoryResolver } from '@angular/core';
import { SampleComponent } from '../sample/sample.component';
@Component({
  selector: 'app-adv',
  templateUrl: './adv.component.html',
  styleUrls: ['./adv.component.css']
})
export class AdvComponent implements OnInit, AfterContentInit {
  @ViewChild('container', {read:'ViewContainerRef'}) container;
  constructor(private resolver : ComponentFactoryResolver) { }

  ngOnInit() {
  }

  ngAfterContentInit(){
    const sampleFactory = this.resolver.resolveComponentFactory(SampleComponent);
    this.container.createComponent(sampleFactory);
  }

}

adv.component.html

<div #container></div>

app.module.ts

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';

import { AppComponent } from './app.component';
import { AdvComponent } from './adv/adv.component';
import { SampleComponent } from './sample/sample.component';

@NgModule({
  declarations: [
    AppComponent,
    AdvComponent,
    SampleComponent
  ],
  entryComponents:[
    SampleComponent
  ],
  imports: [
    BrowserModule
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

Answer 1

关于 ngAfterViewInit docs :

Respond after Angular initializes the component's views and child views.

当 ngAfterContentInit 时:

Respond after Angular projects external content into the component's view.

所以 subview 在ngAfterContentInit中还没有准备好，所以移动这部分

ngAfterContentInit(){
    const sampleFactory = this.resolver.resolveComponentFactory(SampleComponent);
    this.container.createComponent(sampleFactory);
  }

到

ngAfterViewInit() {
    const sampleFactory = this.resolver.resolveComponentFactory(SampleComponent);
    this.container.createComponent(sampleFactory);
}

同时改变:

  @ViewChild('container', {read:'ViewContainerRef'}) container;

到

@ViewChild('container', { read: ViewContainerRef }) container: ViewContainerRef