How to remove Android back buttons on MaterialApp on Flutter?

Question

void main() {
 WidgetsFlutterBinding.ensureInitialized();
 SystemChrome.setEnabledSystemUIOverlays([SystemUiOverlay.bottom]);
 OrientationSingleton.left = true;
 SystemChrome.setPreferredOrientations([DeviceOrientation.landscapeLeft])
 .then((_) {
 runApp(new MyApp());
 });
}
class MyApp extends StatelessWidget {
 // This widget is the root of your application.
 @override
 Widget build(BuildContext context) {
 return MaterialApp(

Here's my app. I've found some tutorials on how to remove it: flutter remove back button on appbar but it's for an AppBar. I tried making my app work on an AppBar but I get

MediaQuery.of() called with a context that does not contain a MediaQuery.

Because I rely on MediaQuery.of() inside my app.

So, how do I remove the Android back, home and square buttons on Flutter for a MaterialApp?

Answer 1

As stated in the error message, SystemChrome requires context - a place to call it could be the initState() method of the Widget:

class MyApp extends StatefulWidget {
 const MyApp({ Key key }) : super(key: key);
 @override
 _MyAppState createState() => _MyAppState();
}
class _MyAppState extends State<MyApp> {
 @override
 void initState() {
 super.initState();
 SystemChrome.setEnabledSystemUIOverlays([SystemUiOverlay.bottom]);
 OrientationSingleton.left = true;
 SystemChrome.setPreferredOrientations([DeviceOrientation.landscapeLeft]);
 }
 @override
 Widget build(BuildContext context) {
 return MaterialApp(); // your MaterialApp class
 }
}

To hide the system bottom bar on Android, one option could be to call the setEnabledSystemUIOverlays() function with an empty list:

SystemChrome.setEnabledSystemUIOverlays([]);

However, this function is not globally supported on all Android devices.

• Poperton: Doing these things in initState() did not work but doing them all on main() like I did worked. Also super.initState(); wasn't possible.
• Stefano Amorelli: I've edited the code to support a Stateful widget, which is required to use the initState() function