How to Show Automatic Internet Connection Offline Message in Flutter

dependencies:
  flutter:
    sdk: flutter
  connectivity_plus: ^6.0.3

import 'dart:async';
import 'package:connectivity_plus/connectivity_plus.dart';
import 'package:flutter/material.dart';

class CheckConnection extends StatefulWidget {
  @override
  _CheckConnectionState createState() => _CheckConnectionState();
}

class _CheckConnectionState extends State<CheckConnection> {
  StreamSubscription? internetConnection;
  bool isOffline = false;
  //set variable for Connectivity subscription listener

  @override
  void initState() {
    internetConnection =
        Connectivity().onConnectivityChanged.listen((connectivityResult) {
      if (connectivityResult.contains(ConnectivityResult.none)) {
        //there is no any connection
        setState(() {
          isOffline = true;
        });
      } else if (connectivityResult.contains(ConnectivityResult.mobile) ||
          connectivityResult.contains(ConnectivityResult.wifi)) {
        //connection is from Wifi or Mobile
        setState(() {
          isOffline = false;
        });
      }
    });
    super.initState();
  }

  @override
  void dispose() {
    super.dispose();
    internetConnection?.cancel();
    //cancel internet connection subscription after you are done
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text(
          "Check Connection",
        ),
      ),
      body: SingleChildScrollView(
        child: Column(
          children: [
            Container(
              child: errorMessage(
                "No Internet Connection Available",
                isOffline,
              ),
              //to show internet connection message on isOffline = true.
            ),
            Container(
              margin: const EdgeInsets.all(
                30,
              ),
              width: double.infinity,
              child: const Center(
                child: Text(
                  "Check Connections",
                  style: TextStyle(
                    fontSize: 20,
                  ),
                ),
              ),
            ),
          ],
        ),
      ),
    );
  }

  Widget errorMessage(
    String text,
    bool show,
  ) {
    //error message widget.
    if (show == true) {
      //if error is true then show error message box
      return Container(
        padding: const EdgeInsets.all(
          10.00,
        ),
        margin: const EdgeInsets.only(
          bottom: 10.00,
        ),
        color: Colors.red,
        child: Row(children: [
          Container(
            margin: const EdgeInsets.only(
              right: 6.00,
            ),
            child: const Icon(
              Icons.info,
              color: Colors.white,
            ),
          ), // icon for error message

          Text(
            text,
            style: const TextStyle(
              color: Colors.white,
            ),
          ),
          //show error message text
        ]),
      );
    } else {
      //if error is false, return empty container.
      return Container();
    }
  }
}