import 'package:flutter/material.dart'; import 'package:checkbox_formfield/checkbox_formfield.dart'; void main() => runApp(MyApp()); class MyApp extends StatelessWidget { // This widget is the root of your application. @override Widget build(BuildContext context) { return MaterialApp( debugShowCheckedModeBanner: false, title: 'Simple Lightweight Todo', theme: ThemeData( primarySwatch: Colors.indigo, accentColor: Colors.blue, disabledColor: Colors.purple, accentIconTheme: IconThemeData( color: Colors.blue, ), ), home: createScaffold(), ); } } Widget createScaffold() { final _formKey = GlobalKey(); return Scaffold( appBar: AppBar( title: Text( 'Sample', ), ), body: Padding( padding: EdgeInsets.all(16), child: Column( children: [ Form( key: _formKey, child: Column( children: [ CheckboxListTileFormField( title: Text('Check!'), onSaved: (bool? value) { print(value); }, validator: (bool? value) { if (value!) { return null; } else { return 'False!'; } }, ), CheckboxIconFormField( initialValue: true, enabled: false, iconSize: 32, onSaved: (bool? value) {}, ), RaisedButton( onPressed: () { if (_formKey.currentState!.validate()) { _formKey.currentState!.save(); } }, child: Text('New'), ), ], ), ), ], ), ), ); }