import 'dart:math' as math;
import 'package:flutter/material.dart';
void main() => runApp(App());
class App extends StatefulWidget {
@override
_AppState createState() => _AppState();
}
class _AppState extends State<App> {
Color color = Colors.red;
@override
Widget build(BuildContext context) {
return MaterialApp(
home: Scaffold(
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Container(
width: 200,
height: 200,
color: color,
),
RaisedButton(
onPressed: () {
setState(() {
color = randomColor();
});
},
child: Text('Random color'),
),
],
),
),
),
);
}
int random(int min, int max) {
final _random = math.Random();
return min + _random.nextInt(max - min + 1);
}
Color randomColor() {
return Color.fromARGB(
random(150, 255), random(0, 255), random(0, 255), random(0, 255));
}
}