ww-sample/bloc_example/lib/screens/web_socket.dart

import 'package:web_socket_channel/web_socket_channel.dart';
import 'package:web_socket_channel/status.dart' as status;

import 'package:flutter/material.dart';

class WebSocketScreen extends StatelessWidget {
  const WebSocketScreen({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('WebSocket Example'),
        leading: IconButton(
          icon: const Icon(Icons.arrow_back),
          onPressed: () => Navigator.pop(context),
        ),
      ),
      body: Center(
        child: Column(
          children: [
            ElevatedButton(
              onPressed: () async {
                connectButtonClicked();
              },
              child: const Text('Connect to WebSocket'),
            ),
            ElevatedButton(
              onPressed: () async {
                sendButtonClicked();
              },
              child: const Text('Send Message'),
            ),
          ],
        ),
      ),
    );
  }
}

void connectButtonClicked() async {
  final wsUrl = Uri.parse('ws://47.76.151.238:82/ws');
  final channel = WebSocketChannel.connect(wsUrl);

  await channel.ready;

  channel.stream.listen((message) {
    print('Received: $message');
  });

  await Future.delayed(Duration(seconds: 2));
  channel.sink.add('Hello World!');
  print('Sent: Hello World!');

  await Future.delayed(Duration(seconds: 2));
  channel.sink.close(status.goingAway);
  print('Connection closed');
}

void sendButtonClicked() async {}