[Angular] Difference between ngAfterViewInit and ngAfterContentInit

Content is what is passed as children. View is the template of the current component.

The view is initialized before the content and ngAfterViewInit() is therefore called before ngAfterContentInit().

@Component({
  selector: 'parent-cmp',
  template: '<div #wrapper><ng-content></ng-content></div>'
})
class ParentComponent {
  @ViewChild('wrapper') wrapper:ElementRef;
  @ContentChild('myContent') content:ElementRef;

  ngAfterViewInit() {
    console.log('ngAfterViewInit - wrapper', this.wrapper);
    console.log('ngAfterViewInit - content', this.content);
  }

  ngAfterContentInit() {
    console.log('ngAfterContentInit - wrapper', this.wrapper);
    console.log('ngAfterContentInit - content', this.content);
  }
}
<parent-cmp><div #myContent>foo</div></parent-cmp>

If you run this code, the output for ngAfterViewInit - content should be null.

So if you want to change the child component's props, you cannot do it in 'ngAfterViewInit', you need to do it in 'ngAfterContentInit'.

原文地址:https://www.cnblogs.com/Answer1215/p/6417872.html