Ionic 2 page change event

Example:
[code type=javascript]
import { Events } from ‘ionic-angular’;

export class BasePage {

constructor(public eventsCtrl: Events) { }

ionViewDidEnter() {
this.eventsCtrl.publish(‘page:load’);
}

ionViewDidUnload() {
this.eventsCtrl.publish(‘page:unload’);
}
}

Referência