一.引入表单模块

app.module.ts

二.news.component.ts

import { Component, OnInit } from '@angular/core';
@Component({
  selector: 'app-news',
  templateUrl: './news.component.html',
  styleUrls: ['./news.component.css']
})
export class NewsComponent implements OnInit {
  msg="";
  constructor() {}
  ngOnInit(): void {
  }
}

三.news.component.html

<h4>双向数据绑定</h4>
<div>
    <input type="text" [(ngModel)]="msg">
    <p>{{msg}}</p>
</div>