1-7生命周期和DOM获取

ngAfterViewInit(){
    //推荐在此生命周期函数中操作DOM
}

1.ViewChild

//1.给DOM命名
<div #app  *ngIf="flag">
    显示
</div>
//2.配置ViewChild
import { Component, OnInit,ViewChild } from '@angular/core';
export class AboutComponent implements OnInit {
  @ViewChild('app',{static:false}) app:any;
  ngAfterViewInit(){
   console.log(this.app);
  }
}