Cupertino widgets in MaterialApp

main.dart

// Copyright (c) 2019, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

import 'package:flutter/material.dart';
import 'package:flutter/cupertino.dart';

void main() => runApp(MyApp());

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

      theme: ThemeData(brightness: Brightness.dark),
      home: CupertinoPageScaffold(
        navigationBar: CupertinoNavigationBar(
          middle: Text(
            'Title',
          ),
          ),
          child: Center(child: Text('text')),
 
        ),
    );
  }
}