Show a confirmation alert before app close ionic 2 - ionic2

Question

I make one application with ionic 2. I am trying to get a confirmation alert before close the application.
How can I do it ?

Answer 1

export class MyApp{
constructor(public alert: AlertController,public platform: Platform){}
exit(){
let alert = this.alert.create({
title: 'Confirm',
message: 'Do you want to exit?',
buttons: [{
text: "exit?",
handler: () => { this.exitApp() }
}, {
text: "Cancel",
role: 'cancel'
}]
})
alert.present();
}
exitApp(){
this.platform.exitApp();
}
}
If you would like to enable back button exit, add event listener for it and call exit function.
You can use this.platform.registerBackButtonAction(this.exit) for it.

Answer 2

I could find by myself the right solution:
https://forum.ionicframework.com/t/show-a-confirmation-alert-before-app-close-ionic/63313
showedAlert: boolean;
constructor(..., public alertCtrl: AlertController) {
}
initializeApp() {
this.platform.ready().then(() => {
// Okay, so the platform is ready and our plugins are available.
// Here you can do any higher level native things you might need.
StatusBar.styleDefault();
Splashscreen.hide();
this.showedAlert = false;
// Confirm exit
this.platform.registerBackButtonAction(() => {
if (this.nav.length() == 1) {
if (!this.showedAlert) {
this.confirmExitApp();
} else {
this.showedAlert = false;
this.confirmAlert.dismiss();
}
}
this.nav.pop();
});
});
}
confirmExitApp() {
this.showedAlert = true;
this.confirmAlert = this.alertCtrl.create({
title: "Salir",
message: "¿ Esta seguro que desea salir de la aplicación ?",
buttons: [
{
text: 'Cancelar',
handler: () => {
this.showedAlert = false;
return;
}
},
{
text: 'Aceptar',
handler: () => {
this.platform.exitApp();
}
}
]
});
this.confirmAlert.present();
}

Answer 3

Ionic 2+ quick solution: In your app.component.ts try
ngOnInit() {
this.platform.registerBackButtonAction(() => {
if (this.nav.canGoBack()) {
this.nav.pop();
} else {
// Currently on root page
this.appClosePromt();
}
}, 1);
}
appClosePromt() {
let alert = this.alertCtrl.create({
title: '',
message: 'Do you want to exit?',
buttons: [
{
text: 'No',
role: 'cancel',
handler: () => {
// Dismiss
}
},
{
text: 'Exit',
handler: () => {
this.platform.exitApp();
}
}
]
});
alert.present();
}