前端学习（2334）：angular之内置属性指令ngclass

child.html

<p>child4 works!</p>

<div class="us">我是歌谣</div>
<div [ngClass]="currentClass" class="col">我是歌谣</div>

child.ts

import { Component, OnInit } from '@angular/core';

@Component({
  selector: 'app-child4',
  templateUrl: './child4.component.html',
  styleUrls: ['./child4.component.css']
})
export class Child4Component implements OnInit {
currentClass(){

}
  constructor() { }

  ngOnInit(): void {
  this.currentClass={
    col:true
  }
  }

}

运行结果