■ 사칙연산 계산기를 만드는 방법을 보여준다.
▶ main.dart
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import 'package:flutter/material.dart'; void main() => runApp(TestApplication()); class TestApplication extends StatelessWidget { static const String _title = 'Test Application'; @override Widget build(BuildContext context) { return MaterialApp( title: _title, home: MainPage(), ); } } class MainPage extends StatefulWidget { MainPage({Key key}) : super(key: key); @override _MainPageState createState() => _MainPageState(); } class _MainPageState extends State<MainPage> { List<String> _buttonTextList = ['더하기', '빼기', '곱하기', '나누기']; List<DropdownMenuItem<String>> _menuItemList = List<DropdownMenuItem<String>>(); String _currentButtonText; String _resultText = ''; TextEditingController controller1 = TextEditingController(); TextEditingController controller2 = TextEditingController(); @override void initState() { super.initState(); for (String buttonText in _buttonTextList) { _menuItemList .add(DropdownMenuItem(value: buttonText, child: Text(buttonText))); } _currentButtonText = _menuItemList[0].value; } Widget build(BuildContext context) { return Scaffold( appBar: AppBar( title: Text('Test Application'), ), body: Container( child: Center( child: Column( children: <Widget>[ Padding( padding: EdgeInsets.all(15), child: Text( '결과 : $_resultText', style: TextStyle(fontSize: 20), ), ), Padding( padding: EdgeInsets.only(left: 20, right: 20), child: TextField( keyboardType: TextInputType.number, controller: controller1, ), ), Padding( padding: EdgeInsets.only(left: 20, right: 20), child: TextField( keyboardType: TextInputType.number, controller: controller2, ), ), Padding( padding: EdgeInsets.all(15), child: RaisedButton( child: Row( children: <Widget>[ Icon(Icons.add), Text(_currentButtonText), ], ), color: Colors.amber, onPressed: () { setState(() { double value1 = double.parse(controller1.value.text); double value2 = double.parse(controller2.value.text); double result; if (_currentButtonText == '더하기') { result = value1 + value2; } else if (_currentButtonText == '빼기') { result = value1 - value2; } else if (_currentButtonText == '곱하기') { result = value1 * value2; } else { result = value1 / value2; } _resultText = result.toString(); }); }), ), Padding( padding: EdgeInsets.all(15), child: DropdownButton( items: _menuItemList, onChanged: (value) { setState(() { _currentButtonText = value; }); }, value: _currentButtonText, ), ), ], ), ), ), ); } } |
