You need a MaterialApp
or a WidgetsApp
around your widget. They provide the MediaQuery
. When you call .of(context)
flutter will always look up the widget tree to find the widget.
You usually have this in your main.dart:
void main() => runApp(App());
class App extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Title',
theme: kThemeData,
home: HomePage(),
);
}
}
class HomePage extends StatelessWidget {
@override
Widget build(BuildContext context) {
final size = MediaQuery.of(context).size;
return Container(
child: ...,
);
}
}