import 'package:flutter/material.dart'; class LoginScreen extends StatefulWidget { const LoginScreen({Key? key, this.onLogin}) : super(key: key); final onLogin; @override _LoginScreenState createState() => _LoginScreenState(); } class _LoginScreenState extends State { @override Widget build(BuildContext context) { return ElevatedButton( onPressed: this.widget.onLogin, child: Text("klick meee")); } }