Counter Number App with Random Color Change App in Flutter

Output Screen

Source Code

import 'package:flutter/material.dart';

import 'dart:math';

void main() {

   

   runApp(MyApp());

}

class MyApp extends StatefulWidget {

  @override

  _MyAppState createState() => _MyAppState();

}

class _MyAppState extends State<MyApp> {

  List<Color> colors = [Colors.blue, Colors.amber, Colors.pink];

  int index=0;

  Color colorrightnow;

  void changecolor() 

  {

    setState(() {

      index=Random().nextInt(colors.length); 

      colorrightnow=colors[index];

    });

  }

  @override

  Widget build(BuildContext context) {

    return MaterialApp(

      title: "Change Color",

      home: Scaffold(

        appBar: AppBar(

          title: Text("Change Color"),

        ),

        backgroundColor: colorrightnow,

        body:Center(

          child: Column(

            mainAxisAlignment: MainAxisAlignment.center,

            children: <Widget>[

              SizedBox(height: 20.0),

                RaisedButton(

                  splashColor: Colors.green,

                  color: Colors.red,

                  onPressed: changecolor,

                  child: Text("Click Here",

                  style: TextStyle(

                    fontSize: 20.0,

                    color: Colors.white,

                  ),

                  ),

                )

            ],

          ),  

        ),

      ),

    );

  }

}