老规矩效果图：
第一步：引入
web_socket_channel: ^2.4.0第二步：封装 websocket.dart 单例
import 'dart:async';
import 'dart:convert';
import 'package:web_socket_channel/web_socket_channel.dart';
import 'package:web_socket_channel/io.dart';class WebSocketManager {late WebSocketChannel _channel;final String _serverUrl; //ws连接路径final String _accessToken; //登录携带的tokenbool _isConnected = false; //连接状态bool _isManuallyDisconnected = false; //是否为主动断开late Timer _heartbeatTimer; //心跳定时器late Timer _reconnectTimer; //重新连接定时器Duration _reconnectInterval = Duration(seconds: 5); //重新连接间隔时间StreamController<String> _messageController = StreamController<String>();Stream<String> get messageStream => _messageController.stream; //监听的消息//初始化WebSocketManager(this._serverUrl, this._accessToken) {print('初始化');_heartbeatTimer = Timer(Duration(seconds: 0), () {});_startConnection();}//建立连接void _startConnection() async {try {_channel = WebSocketChannel.connect(Uri.parse(_serverUrl));print('建立连接');_isConnected = true;_channel.stream.listen((data) {_isConnected = true;print('已连接$data');final jsonObj = jsonDecode(data); // 将消息对象转换为 JSON 字符串if (jsonObj['cmd'] == 0) {_startHeartbeat(); //开始心跳} else if (jsonObj['cmd'] == 1) {_resetHeartbeat(); // 重新开启心跳定时} else {_onMessageReceived(data);// 其他消息转发出去}},onError: (error) {// 处理连接错误print('连接错误: $error');_onError(error);},onDone: _onDone,);_sendInitialData(); // 连接成功后发送登录信息();} catch (e) {// 连接错误处理print('连接异常错误: $e');_onError(e);}}//断开连接void disconnect() {print('断开连接');_isConnected = false;_isManuallyDisconnected = true;_stopHeartbeat();_messageController.close();_channel.sink.close();}//开始心跳void _startHeartbeat() {_heartbeatTimer = Timer.periodic(Duration(seconds: 20), (_) {sendHeartbeat();});}//停止心跳void _stopHeartbeat() {_heartbeatTimer.cancel();}//重置心跳void _resetHeartbeat() {_stopHeartbeat();_startHeartbeat(); //开始心跳}// 发送心跳消息到服务器void sendHeartbeat() {if (_isConnected) {final message = {"cmd": 1, "data": {}};final jsonString = jsonEncode(message); // 将消息对象转换为 JSON 字符串_channel.sink.add(jsonString); // 发送心跳print('连接成功发送心跳消息到服务器$message');}}// 登录void _sendInitialData() async {try {final message = {"cmd": 0,"data": {"accessToken": _accessToken}};final jsonString = jsonEncode(message); // 将消息对象转换为 JSON 字符串_channel.sink.add(jsonString); // 发送 JSON 字符串print('连接成功-发送登录信息$message');} catch (e) {// 连接错误处理print('连接异常错误: $e');_onError(e);}}//发送信息void sendMessage(dynamic message) {final data = {"cmd":3,"data":message};final jsonString = jsonEncode(data); // 将消息对象转换为 JSON 字符串_channel.sink.add(jsonString); // 发送 JSON 字符串}// 处理接收到的消息void _onMessageReceived(dynamic message) {print('处理接收到的消息Received===========================================: $message');_messageController.add(message);}//异常void _onError(dynamic error) {// 处理错误print('Error: $error');_isConnected = false;_stopHeartbeat();if (!_isManuallyDisconnected) {// 如果不是主动断开连接，则尝试重连_reconnect();}}//关闭void _onDone() {print('WebSocket 连接已关闭');_isConnected = false;_stopHeartbeat();if (!_isManuallyDisconnected) {// 如果不是主动断开连接，则尝试重连_reconnect();}}// 重连void _reconnect() {// 避免频繁重连，启动重连定时器_reconnectTimer = Timer(_reconnectInterval, () {_isConnected = false;_channel.sink.close(); // 关闭之前的连接print('重连==============&
