Angular 6在单个函数中管理多个请求

import { Component } from '@angular/core';
import { HttpClient } from '@angular/common/http';
import { forkJoin } from 'rxjs';

@Component({
  selector: 'app-example',
  template: `
    <button (click)="getData()">Get Data</button>
    <div *ngIf="data">
      <h2>Data:</h2>
      <ul>
        <li *ngFor="let item of data">{{ item }}</li>
      </ul>
    </div>
  `,
})
export class ExampleComponent {
  data: any[];

  constructor(private http: HttpClient) {}

  getData() {
    const request1 = this.http.get('https://api.example.com/data1');
    const request2 = this.http.get('https://api.example.com/data2');
    const request3 = this.http.get('https://api.example.com/data3');

    forkJoin([request1, request2, request3]).subscribe(
      (response) => {
        this.data = response;
      },
      (error) => {
        console.error(error);
      }
    );
  }
}