flutter

https://www.youtube.com/watch?v=8KFYJSdsBLs&list=PLnIaYcDMsScxP2Nl8pEbmI__wkF0YVu0a&index=4 

c:\Users\newstep\StudioProjects\my_first_flutter\lib\main.dart----------

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(title: 'Flutter Demo Home Page 정용만')
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({Key ? key,  required this.title}) : super(key: key);
  final String title;
  @override
  _MyHomePageState createState() => _MyHomePageState();
}


class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text(widget.title),),
      body: Center(
        child: Column(mainAxisAlignment: MainAxisAlignment.center,
        children: <Widget>[
          Text('You have pushed the button this many times:'),
          Text('$_counter', style: Theme.of(context).textTheme.displaySmall)
        ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: Icon(Icons.add)
      ),
    );
  }

  void _incrementCounter() {
    setState(() {
      _counter++;
    });
  }
}