如何在Flutter上删除MaterialApp上的Android后退按钮？

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(

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

那么，如何删除MaterialApp的Flutter上的Android back、home和square按钮呢？

Answer 1

正如错误消息中所述，SystemChrome需要Context-调用它的位置可以是小部件的initstate()方法：

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
   }
}

要在Android上隐藏系统底栏，一种方法是调用setenabledsystemUiOverays()函数，其中包含一个空列表：

SystemChrome.setEnabledSystemUIOverlays([]);

然而，并不是所有Android设备都支持这项功能。