| // 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'), |
| ), |
| ), |
| ], |
| ), |
| ); |
| } |
| } |