플러터[flutter] 기초 정리 1

■ 정보

1. 변경 없는 위젯(statelessWidget) vs 변경 있는 위젯(staefuleWidget)

2. 플러터는 모든것이 위젯( 텍스트, 버튼, 화면구성 등 모든 컴포넌트 및 레이아웃이 위젯임!! )

3. 배경위젯위에 다양한 위젯들을 겹겹히 쌓아올려서 만드는 방식

4. 머터리얼앱 - 구글머터리얼 디자인을 사용하기 위해서 사용

5. 스캐폴드 - 구글 머터리얼 디자인의 구조를 잡아줌

import 'package:flutter/material.dart';

void main() => runApp(MyApp()); //MAIN 실행

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        // This is the theme of your application.

        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page2'), //MyHomePage 실행
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  // This widget is the home page of your application. It is stateful, meaning

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState(); //_MyHomePageState 실행
}

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

  void _incrementCounter() {
    setState(() {
      // This call to setState tells the Flutter framework that something has
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {
    // This method is rerun every time setState is called, for instance as done
    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.display1,
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: Icon(Icons.add),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }
}

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