**이 페이지에서 알 수 있는 내용 このページからわかること

- Scaffold
	- appBar
	- body**
	

...
...

@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.headlineMedium)
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: const Icon(Icons.add),
      ),
    );
  }
}

main.dart