如何在Ionicframework中输出异步/可观测数据？

npm install rxjs

import { Injectable } from '@angular/core';
import { Observable } from 'rxjs';

@Injectable({
  providedIn: 'root'
})
export class DataService {
  private data: Observable<any>;

  constructor() { }

  getData(): Observable<any> {
    // 模拟异步数据请求
    this.data = new Observable(observer => {
      setTimeout(() => {
        observer.next('这是异步数据');
        observer.complete();
      }, 2000);
    });

    return this.data;
  }
}

import { Component } from '@angular/core';
import { DataService } from './data.service';

@Component({
  selector: 'app-root',
  template: `
    <div>{{ asyncData }}</div>
  `
})
export class AppComponent {
  asyncData: any;

  constructor(private dataService: DataService) { }

  ngOnInit() {
    this.dataService.getData().subscribe(data => {
      this.asyncData = data;
    });
  }
}