헬로월드 어플로 해보기!

import 'package:flutter/material.dart';


void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(),
);
}
}

class MyHomePage extends StatefulWidget {
@override
_MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage>{
var _text = 'Hellow';

@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('Hellow World'),
),
body: Text(
_text,
style: TextStyle(fontSize: 40),
),
floatingActionButton: FloatingActionButton(
onPressed: (){    // 클릭하면 hello에서 world로 바뀜
setState(() {
_text = 'World';
});
},
child: Icon(Icons.touch_app),
),
);
}
}