why does mediaquery.of() error keep showing up? - flutter

Question

I am just trying to create an simple widget but it keeps showing this error what should I do?

Answer 1

It looks like your root widget is not MaterialApp, other widgets that you are using need to be descendants of some media query ancestor. Eg. MaterialApp.
Instead of this:
Widget build(BuildContext context) {
return Container(
child: SomeWidget(),
);
}
Make it:
Widget build(BuildContext context) {
return MaterialApp(
home: SomeWidget(),
);
}

Answer 2

You are getting the error because your application doesn't return a Material App. Check this code below, it works perfectly.
import 'package:flutter/material.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
// This widget is the root of your application.
#override
Widget build(BuildContext context) {
return MaterialApp(
home: Scaffold(
appBar: AppBar(
backgroundColor: Colors.redAccent,
title: Text('unit converter', textScaleFactor: 1.0,),
),
body: Container(
color: Colors.purpleAccent,
),
),
);
}
}
The output of the code:

Answer 3

You are getting this error because on the top of the tree a material widget should be used.
here you can use Scaffold or MaterialApp widget.
and If you are trying to paint your screen background to some color then just use the parameter backgroundColor under your Scaffold widget.
Try code shown below
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Colors.purpleAccent,
appBar: AppBar(
backgroundColor: Colors.redAccent,
title: Text("unit converter",textScaleFactor:4.0)
),
body: yourWidget()
);
}