【Flutter】io库里自带的WebSocket使用

import 'dart:io';

class LCWebSocketManager {
  LCWebSocketManager._();
  static LCWebSocketManager _manager;
  factory LCWebSocketManager() {
    if (_manager == null) {
      _manager = LCWebSocketManager._();
    }
    return _manager;
  }

  WebSocket _webSocket;

  initWebSocket({Function success, Function failure}) async {
    var _linkAddress = "ws://62.234.***.***:5300?token=";
    var token = "";

    try {
      _webSocket = await WebSocket.connect(_linkAddress + token);
      print("【WebSocket】创建链接");
      if (_webSocket.readyState == WebSocket.open) {
        success();
        _ping();
        _webSocket.listen((onData) {
          print("【WebSocket】接收到消息 == > $onData");
          _chengaMessage(onData);

        }, onError: (error) {
          print("【WebSocket】错误 == > $error");
        }, onDone: () {
          print("【WebSocket】结束链接");
        });
      } else {
        failure();
        return;
      }
    } catch (e) {
      failure();
      return;
    }
  }
  
  /// 发送心跳包
  _ping() {
    Future.delayed(Duration(seconds: 3)).then((value) {
      if (_webSocket.readyState == WebSocket.open) {
        _webSocket.add("hello, my name is lichuang!");
        _ping();
      }
    });
  }
  
  /// 发送消息
  sendMessage() {
    _webSocket.add("hello, my name is lilei!");
  }

  /// 关闭
  closeConnect() {
    _webSocket.close();
  }

  /// 当前状态
  currentState() {
    switch (_webSocket.readyState) {
      case WebSocket.connecting:
        print('【WebSocket】当前状态 ==> connecting');
        break;
      case WebSocket.open:
        print('【WebSocket】当前状态 ==> open');
        break;
      case WebSocket.closing:
        print('【WebSocket】当前状态 ==> closing');
        break;
      case WebSocket.closed:
        print('【WebSocket】当前状态 ==> closed');
        break;
      default:
    }
  }
  
  /// 处理接收到的消息
  _chengaMessage(dynamic data) {
    var model = ReceiveMessageModel.fromJson(convert.jsonDecode(data));
    if (model.type == 0) {
      print("【WebSocket】消息消息");
      TTSUtil().initTTS();
      TTSUtil().speak(model.data.label);
    } else if (model.type == 1) {
      print("【WebSocket】我是心跳");
    } else if (model.type == 2) {
      print("【WebSocket】链接成功");
    }
  }
}

class ReceiveMessageModel {
  int type;
  ReceiveMessageDetailModel data;
  ReceiveMessageModel.fromJson(Map<String, dynamic> json) {
    type = json['type'];
    data = ReceiveMessageDetailModel.fromJson(json['data']);
  }
}

class ReceiveMessageDetailModel {
  int id;
  String label;
  ReceiveMessageDetailModel.fromJson(Map<String, dynamic> json)
      : id = json['id'],
        label = json['label'];
}