javascript - App and Nav in ionic2

Question

What is the difference between this.app.getRootNav() and this.navCtrl.push()? In fact, the main reason is that I don’t understand the relationship and difference between the App component and Nav? Also, the tabs component does not refresh when switching tabs. Is there any way to refresh the page when switching? Ask God for advice.

習慣沉默 · Answer

Second question, you can try the life cycle of NavController in the official API and add ionViewDidEnter(){}