content: import 'package:flutter/material.dart';
  
  void main() {
    runApp(App());
  }
  
  class App extends StatelessWidget {
    @override
    Widget build(BuildContext context) {
      return MaterialApp(
        title: "Tutorial 10",
        home: HomePage(),
      );
    }
  }
  
  class HomePage extends StatefulWidget {
    @override
    _HomePageState createState() => _HomePageState();
  }
  
  class _HomePageState extends State<HomePage> {
    int count = 0;
  
    void increment() {
      setState(() {
        count = count + 1;
        print(count);
      });
    }
  
    @override
    Widget build(BuildContext context) {
      return Scaffold(
        appBar: AppBar(
          title: Text('Tutorial 10'),
        ),
        body: Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              Text(
                'You have pushed button times',
                style: TextStyle(fontSize: 25.0),
              ),
              Text(
                '$count',
                style: Theme.of(context).textTheme.display1,
              )
            ],
          ),
        ),
        floatingActionButton: FloatingActionButton(
          child: Icon(Icons.add),
          onPressed: increment,
        ),
      );
    }
  }
  