如何在angular中使用@input/@output在组件之间共享数据？

<app-child [data]="parentData"></app-child>

export class ParentComponent {
  parentData: string = "Hello from parent";

  constructor() { }
}

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

@Component({
  selector: 'app-child',
  template: '<p>{{ childData }}</p>'
})
export class ChildComponent {
  @Input() data: string;
  childData: string;

  constructor() {
    this.childData = this.data;
  }
}

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

@Component({
  selector: 'app-child',
  template: '<button (click)="sendData()">Send Data</button>'
})
export class ChildComponent {
  @Output() dataEvent: EventEmitter<string> = new EventEmitter<string>();

  constructor() { }

  sendData() {
    const data: string = "Hello from child";
    this.dataEvent.emit(data);
  }
}

export class ParentComponent {
  receivedData: string;

  constructor() { }

  receiveData(data: string) {
    this.receivedData = data;
  }
}