与 Xamarin.Forms Android 项目建立 WebSocket4Net 连接时遇到问题

Posted 2023-02-16

【中文标题】与 Xamarin.Forms Android 项目建立 WebSocket4Net 连接时遇到问题

【英文标题】：Trouble establishing WebSocket4Net connection with Xamarin.Forms Android project

【发布时间】：2019-09-26 15:26:51

【问题描述】：

我们最近重新组织了套接字连接，让它们使用更多共享代码。我目前的 ios 项目能够连接到 Web 套接字并响应事件，但我还没有成功使用 android 项目。它将尝试连接并最终使用“传输错误”的数据触发断开连接事件。我想知道是否有更多使用套接字经验的人知道 iOS 连接和 android 连接之间是否存在任何关键区别？我将在下面发布我的一些代码，并尝试删除我认为不相关的块。谢谢！！

这是我的共享课

        public bool InitAndConnect()
        

            //Create a socket
            sock = DependencyService.Get<IDabSocket>(DependencyFetchTarget.NewInstance);

            //Get the URL to use
            ContentConfig config = ContentConfig.Instance;
            string uri;
            if (GlobalResources.TestMode)
            
                uri = config.app_settings.stage_journal_link;
            
            else
            
                uri = config.app_settings.prod_journal_link;
            

            //Create list of events to monitor (basic connection events are already monitored)
            List<String> events = new List<String>();
            events.Add("room_error");
            events.Add("join_error");
            events.Add("auth_error");
            events.Add("update");

            //Register for notifications from the socket
            sock.DabSocketEvent += Sock_DabSocketEvent;

            //Init the socket
            sock.Init(uri, events);

            //Connect the socket
            sock.Connect();

            return true;
        

        public bool JoinRoom(DateTime date)
        
            //Joins a room for a specific date
            var room = date.ToString("yyyy-MM-dd");
            var token = AuthenticationAPI.CurrentToken;
            var data = new DabJournalObject(room, token);
            var json = JObject.FromObject(data);
            //Send data to the socket
            sock.Emit("join", json);
            //Store the date we're using
            currentDate = date;

            return true;
        

        //IsConnected returns a bool indicating whether the socket is currently connected.
        //This is a bindable property
        public bool IsConnected
        
            get
            
                return sock == null ? false : sock.IsConnected;
            
        

        //Opposite of IsConnected used for binding reasons.
        public bool IsDisconnected
        
            get
            
                return sock == null ? true : !sock.IsConnected;
            

        

        private void Sock_DabSocketEvent(object sender, DabSocketEventHandler e)
        
            //An event has been fired by the socket. Respond accordingly

            //Log the event to the debugger
            Debug.WriteLine($"e.eventName was fired with e.data");

            //Take action on the event
            switch (e.eventName.ToLower())
            
                case "disconnected": //Socket disconnected
                    Sock_Disconnected(e.data);
                    break;
                case "connected": //Socket connected
                    Sock_Connected(e.data);
                    break;
                case "reconnecting": //Socket reconnecting
                    sock.Connect();
                    //do nothing for now
                    break;
                case "reconnected": //Socket reconnected
                    Sock_Connected(e.data);
                    break;
                case "room_error": //Error with a room
                    Sock_ErrorOccured(e.eventName, e.data);
                    break;
                case "join_error": //Error joining
                    Sock_ErrorOccured(e.eventName, e.data);
                    break;
                case "auth_error": //Error with authentication
                    Sock_ErrorOccured(e.eventName, e.data);
                    break;
                case "update": //update happened externally
                    Sock_ExternalUpdateOccured(e.eventName, e.data);
                    break;
                default:
                    break;
            
        

        private void Sock_Disconnected(string data)
        
            //The socket got disconnected.

            //Notify UI
            OnPropertyChanged("IsConnected");
            OnPropertyChanged("IsDisconnected");
        

        private void Sock_Connected(object data)
        
            //The socket has connected or reconnected. Take appropriate action

            //Notify UI
            OnPropertyChanged("IsConnected");
            OnPropertyChanged("IsDisconnected");
        

        /* Events to handle Binding */
        public virtual void OnPropertyChanged(string propertyName = null)
        
            var handler = PropertyChanged;
            if (handler != null)
                handler(this, new PropertyChangedEventArgs(propertyName));
        
    

这是我的安卓类

       public bool IsConnected
       
           get
           
               return isConnected;
           
       
       public void Connect(string token)
       
           //Make sure the socket is initialized
           if (!isInitialized) throw new Exception("You must initialize the socket before using it");
           sock.Connect();
       
       public void Init(string Uri, List<String> events)
       
           //Initialize the socket
           try
           
               sock = IO.Socket(Uri);
               isInitialized = true;
               //Set up standard events
               sock.On("connect", data => OnConnect(data));
               sock.On("disconnect", data => OnDisconnect(data));
               sock.On("reconnect", data => OnReconnect(data));
               sock.On("reconnecting", data => OnReconnecting(data));
               //Set up custom events requested by the caller
               foreach (string s in events)
               
                   sock.On(s, data => OnEvent(s, data));
               
           
           catch (Exception ex)
           
               isInitialized = false;
               isConnected = false;
           
       
       private object OnEvent(string s, object data)
       
           //A requested event has fired - notify the calling app so it can handle it.
           //Notify the listener
           DabSocketEvent?.Invoke(this, new DabSocketEventHandler(s, data.ToString()));
           return data;
       
       private object OnConnect(object data)
       
           //Socket has connected (1st time)
           isConnected = true;
           //Notify the listener
           DabSocketEvent?.Invoke(this, new DabSocketEventHandler("connected", data.ToString()));
           //Return
           return data;
       
       private object OnDisconnect(object data)
       
           //Socket has disconnected
           isConnected = false;
           //Notify the listener
           DabSocketEvent?.Invoke(this, new DabSocketEventHandler("disconnected", data.ToString()));
           //Return
           return data;
       
       public void Disconnect()
       
           if (IsConnected)
           
               sock.Disconnect();
           
       
       public void Connect()
       
           sock.Connect();
       
       public void Emit(string Command, object Data)
       
           sock.Emit(Command, Data);
       
       public void Open()
       
           sock.Open();
       

我的 iOS 类看起来非常类似于 droid 类.. 除了 Open().. 不知道 android 端挂了什么。

【问题讨论】：

在android中建立WebSocket4Net连接时，能否请您发布一些错误信息？

我现在正在运行代码，但我并没有真正得到任何错误，它只是没有在 android 端建立连接。不断返回false。我初始化并尝试连接套接字，然后尝试加入房间，但到目前为止我无法建立与套接字的连接。

在我的三元运算符中，出于某种原因，我的 iOS 类正在适当地返回 sock.IsConnected，但在上面的 droid 类中，它总是返回 sock.IsConnected == false。 @JessieZhang

您可以尝试逐步调试请求，然后您可以看到有关此问题的详细信息。

【参考方案1】：

我的 SocketIoClientDotNet nuget 包版本在我的 iOS 和 android 项目之间不匹配。一旦我更新了我的 android 包以匹配 iOS 项目中的版本，一切都很好。