How Can I Update Image after few seconds in flutter?

Question

I'm Building An Flutter Application which requires image changes after a period of time. I thought using while loop with a sleep method inside may solve the problem. But It didn't, Image is only getting change after the loop ends. Application UI also gets froze.

Desired Output: Image should be changed after every 10 seconds.

Image and Button text is not Updating When Loop is running, please help me to get the desired output.

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
  return MaterialApp(
    home: Scaffold(
      body: Center(
        child: Test(
        ),
      ),
    )
  );
  }}
class Test extends StatefulWidget {
  @override
  _TestState createState() => _TestState();
}

class _TestState extends State<Test> {
  int imgnumber=1;
  int varToCheckButtonPress = 0;
  String BtnTxt = "START";
  void inc(){
    while(imgnumber<10)
      {
        print(imgnumber);
        setState(() {
          sleep(Duration(seconds:5));
          imgnumber++;
        });
      }
  }
  @override
  Widget build(BuildContext context) {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.stretch,
      children: <Widget>[
        Expanded(flex: 1,
          child: Container(
            child: Image.asset('images/'+imgnumber.toString()+'.png'),
            height: 500,
            width:500,
            color: Colors.green,
          ),
        ),
        FlatButton(
          child: Text(BtnTxt),
          onPressed: (){
            if (varToCheckButtonPress == 0) {
              setState(() {
                BtnTxt = 'PAUSE';
                varToCheckButtonPress = 1;
              });
            } else if (varToCheckButtonPress == 1) {
              setState(() {
                BtnTxt = 'RESUME';
                varToCheckButtonPress = 0;
              });
            }
            inc();
          },
        )
      ],
    );
  }
}

Answer 1

you shouldn't use sleep in the setState try replacing the inc function with this:

void inc() async {
    while(imgnumber<10)
      {
        print(imgnumber);
        await Future.delayed(const Duration(seconds: 10));
        setState(() {
          imgnumber++;
        });
      }
  }