Ionic4 hardware mobile back buttion issue - ionic-framework

Question

if click on the back button to close ionic4 app in android mobile getting following error
code to close the app:
ionViewDidEnter() {
this.subscription = this.platform.backButton.subscribe(async () => {
navigator['app'].exitApp();
});
}
ionViewWillLeave() {
this.subscription.unsubscribe();
}
error:
E/Capacitor/Plugin/Console: ERROR Error: Uncaught (in promise): Error: StaticInjectorError[t -> t]:
StaticInjectorError(Platform: core)[t -> t]:
NullInjectorError: No provider for t!
Error: StaticInjectorError[t -> t]:
StaticInjectorError(Platform: core)[t -> t]:
NullInjectorError: No provider for t!

Answer 1

Please refer to this snippet workaround
this.platform.backButton.subscribe(() => {
// code that is executed when the user pressed the back button
})
// To prevent interference with ionic's own backbutton handling
// you can subscribe with a low priority instead
this.platform.backButton.subscribeWithPriority(0, () => {
// code that is executed when the user pressed the back button
// and ionic doesn't already know what to do (close modals etc...)
})
PS: Hope you'd check whether platform module is imported or not.
import { Platform } from '#ionic/angular';
#Component({...})
export class MyPage {
constructor(public plt: Platform) {
}
}