[网络协议]Flutter WebSocket

再开发过程中我们经常会使用到WebSocket，而插件库为我们提供了一个使用非常方便的插件

web_socket_channel

我们需要根据自己的Flutter 版本选择对应的即可

web_socket_channel: ^1.1.0

在pubspec.yaml中我们引入，然后pub get 一下

pub get

到此就完成插件的引用。下面就是使用了

官网的代码使用

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

main() async {
  var channel = IOWebSocketChannel.connect(Uri.parse('ws://localhost:1234'));

  channel.stream.listen((message) {
    channel.sink.add('received!');
    channel.sink.close(status.goingAway);
  });
}

下面是我对其进行了简单的封装

import 'dart:convert';
import 'package:flutter/foundation.dart';
import 'package:jianfa/view/main/my/message/detail/MessageDetailSocket.dart';
import 'package:jianfa/widget/CustomDialog.dart';
import 'package:web_socket_channel/io.dart';
import 'package:flutter/material.dart';
import 'package:web_socket_channel/web_socket_channel.dart';


class WebSocketChannel {
  // 创建WebSocketChannel 单利，全局只有一个对象
  WebSocketChannel._privateConstructor();

  static final WebSocketChannel _instance =
      WebSocketChannel._privateConstructor();

  static WebSocketChannel get instance {
    return _instance;
  }
    
  BuildContext contexts;

  
  IOWebSocketChannel channel;
   
  // 开始进行链接
  void connect(BuildContext context) {
    contexts = context;
    channel = IOWebSocketChannel.connect(
        "ws://localhost:1234");
    sendMessage();
    channel.stream.listen(this.onData, onError: onError, onDone: onDone);
  }

  // 发送消息
  void sendMessage() {
    channel.sink.add("");
  }

  // 断连，然后执行重连
  onDone() {
    debugPrint("Socket is closed");
    channel = IOWebSocketChannel.connect(
        "ws://localhost:1234");
    channel.stream.listen(this.onData, onError: onError, onDone: onDone);
    (() async {});
  }
  
  // 错误日志
  onError(err) {
    debugPrint(err.runtimeType.toString());
    WebSocketChannelException ex = err;
    debugPrint(ex.message);
  }

  // 接受数据，数据json字符串，然后转成Map
  onData(event) {
    print('收到消息:' + event);
    Map<String, dynamic> map = json.decode(event);
    
  }

  void dispose() {
    channel.sink.close();
  }
}

下面是使用

// 创建对象
WebSocketChannel webSocketChannel = WebSocketChannel.instance;

// 开始进行链接
webSocketChannel.connect(context);

// 断开链接
webSocketChannel.dispose();

到此就完成了web_socket_channel的简单封装和基本使用。