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

void main() => runApp(
MaterialApp(
home: BallPage(),
),
);

class BallPage extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Colors.blue,
appBar: AppBar(
backgroundColor: Colors.blue.shade900,
title: Text('Ask Me Anything'),
),
body: Ball(),
);
}
}

class Ball extends StatefulWidget {
@override
_BallState createState() => _BallState();
}

class _BallState extends State<Ball> {
    int ballNumber = 1;

    @override
    Widget build(BuildContext context) {
    return Center(
    child: FlatButton(
    onPressed: () {
    setState(() {
    ballNumber = Random().nextInt(5) + 1;
    });
    },
    child: Image.asset('images/ball$ballNumber.png'),
    ),
    );
    }
    }