Flutter SnackBars Example 02

# Flutter SnackBars Example 02

import 'package:flutter/material.dart';
 
/*
  Snackbar Widget 을 사용하려면 Scaffold widget 을 사용해야 함

  # SnackBars Widget 을 만드는 순서
  1. Create a Scaffold
  2. Display a SnackBar
  3. Provide an additional action

  SnackBars 만들 때 SnackBar 내용은 따로 Widget 을 만들지 않을 경우에는
  build() 를 이용해서 context를 인자값으로 전달 후 생성
*/
class SnackBarsEx02 extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('SnackBarsEx02'),
      ),
      body: Builder(
        builder: (context) => Center(
              child: RaisedButton(
                onPressed: () {
                  final snackBar = SnackBar(
                    content: Text('Yay! A SnackBar!'),
                    action: SnackBarAction(
                      label: 'Undo',
                      onPressed: () {
                        // Some code to undo the change!
                      },
                    ),
                  );
 
                  // Find the Scaffold in the Widget tree and use it to show a SnackBar!
                  Scaffold.of(context).showSnackBar(snackBar);
                },
                child: Text('Show SnackBar'),
              ),
            ),
      ),
    );
  }
}