// Copyright 2014 The Flutter Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. // Flutter code sample for Form import 'package:flutter/material.dart'; void main() => runApp(const MyApp()); class MyApp extends StatelessWidget { const MyApp({super.key}); static const String _title = 'Flutter Code Sample'; @override Widget build(BuildContext context) { return MaterialApp( title: _title, home: Scaffold( appBar: AppBar(title: const Text(_title)), body: const MyStatefulWidget(), ), ); } } class MyStatefulWidget extends StatefulWidget { const MyStatefulWidget({super.key}); @override State<MyStatefulWidget> createState() => _MyStatefulWidgetState(); } class _MyStatefulWidgetState extends State<MyStatefulWidget> { final GlobalKey<FormState> _formKey = GlobalKey<FormState>(); @override Widget build(BuildContext context) { return Form( key: _formKey, child: Column( crossAxisAlignment: CrossAxisAlignment.start, children: <Widget>[ TextFormField( decoration: const InputDecoration( hintText: 'Enter your email', ), validator: (String? value) { if (value == null || value.isEmpty) { return 'Please enter some text'; } return null; }, ), Padding( padding: const EdgeInsets.symmetric(vertical: 16.0), child: ElevatedButton( onPressed: () { // Validate will return true if the form is valid, or false if // the form is invalid. if (_formKey.currentState!.validate()) { // Process data. } }, child: const Text('Submit'), ), ), ], ), ); } }