Im new in development, so Im having trouble with my screenutilinit function. I have added the dependencies ' flutter_screenutil: ^4.0.2+3 ' in the pubspec.yaml file but it has error saying 'The method 'ScreenUtilInit' isn't defined for the class 'MyApp'.

  • 'MyApp' is from 'package:sparks/main.dart' ('lib/main.dart').'

Last time the code works (fine) for my design but since I migrated my project files into new folder, it has the red underline beneath it. Can anyone tell me why?

additional note: I migrated the project files into new folder because I was having trouble with my firebase set up, thus I decided to create a new project and copy and paste the lib files into the new project.

here is my main.dart:

import 'package:flutter/material.dart';
import 'package:flutter_screenutil/flutter_screenutil.dart';
import 'package:sparks/screens/Welcomecomponent/welcome.dart';

void main() {

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  Widget build(BuildContext context) {
    return ScreenUtilInit(
        designSize: Size(414, 896), allowFontScaling: false,
        child: MaterialApp(
          title: 'Spark',
          theme: ThemeData(
            //primarySwatch: Colors.white,
            visualDensity: VisualDensity.adaptivePlatformDensity,
          home: WelcomeScreen(),

this is my pubspec.yaml file:

name: sparks
description: A new Flutter project.

  sdk: ">=2.7.0 <3.0.0"

    sdk: flutter

  cupertino_icons: ^1.0.0
  flutter_screenutil: ^4.0.2+3

    sdk: flutter


  uses-material-design: true

    - assets/images/
    - assets/icons/
    - assets/fonts/

here is the error: enter image description here

Solution 1: Mayur Chaudhary

The Widget you are trying to use needs a parameter called builder(). and ScreenUtilInit doesn't accept child: parameter.

Try this:

  designSize: Size(360, 690),
  allowFontScaling: false,
  builder: () => MaterialApp(
    debugShowCheckedModeBanner: false,
    title: 'Flutter_ScreenUtil',
    theme: ThemeData(
    home: HomePage(),