Ionic 3:如果在函数subscribe()内部返回on

import { Component } from '@angular/core';
import { Observable, Subscription } from 'rxjs';

@Component({
  selector: 'app-example',
  template: `
    <button (click)="startSubscription()">Start Subscription</button>
  `
})
export class ExampleComponent {
  private subscription: Subscription;

  startSubscription() {
    const observable: Observable<any> = ...; // 创建一个Observable对象

    this.subscription = observable.subscribe(
      (data) => {
        // 处理数据的回调函数
        console.log(data);
      },
      (error) => {
        // 处理错误的回调函数
        console.error(error);
      },
      () => {
        // 完成订阅的回调函数
        console.log('Subscription completed');
      }
    );
  }

  ngOnDestroy() {
    if (this.subscription) {
      this.subscription.unsubscribe(); // 取消订阅
    }
  }
}