import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
        visualDensity: VisualDensity.adaptivePlatformDensity,
      ),
      home: Home(),
    );
  }
}

class Home extends StatelessWidget {
  const Home({Key key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(),
      body: Center(
        child: Builder(
          builder: (context) => FlatButton(
            child: Text(
              "Click to show snackbar",
              style: TextStyle(color: Theme.of(context).primaryColor),
            ),
            onPressed: () {
              Scaffold.of(context).showSnackBar(
                SnackBar(
                  content: Text("This is a snackbar!"),
                ),
              );
            },
          ),
        ),
      ),
    );
  }
}