Asynchronous message sending WCF

Question

The addMessage method asynchronously sends messages to clients.

The problem is that those who send it receive it themselves

That is, the client hears himself

    public void AddMessage(byte[] message)
    {

          IAsyncMessageCallback other = OperationContext.Current.GetCallbackChannel<IAsyncMessageCallback>();
          other.BeginOnMessageAdded(message, DateTime.Now, delegate (IAsyncResult ar)
                {
                    other.EndOnMessageAdded(ar);
                }, null);


    }

I tried to implement it in the following way:

 public void AddMessage(byte[] message)
        {
            lock (subscribers)
            {
                var connection = OperationContext.Current.GetCallbackChannel<IAsyncMessageCallback>();

                string user;
                if (!subscribers.TryGetValue(connection, out user))
                    return;
                foreach (var other in subscribers.Keys)
                {
                    //Console.WriteLine(other + " " + connection);
                    if (other == connection)
                        continue;
                    Console.WriteLine(other + " " + connection);
                    other.BeginOnMessageAdded(message, DateTime.Now, delegate (IAsyncResult ar)
                    {
                        other.EndOnMessageAdded(ar);
                    }, null);
                    Console.WriteLine(message.Length);
                }
            }
          }

But this leads to terrible brakes

Thank you in advance

Answer 1

Hi @Naydachy ,
You want to publish the last received message to every client except the one who sent it, you would:

lock (subscribers)  
        {  
            foreach (var _subscriber in subscribers)  
            {  
                if (OperationContext.Current.GetCallbackChannel<IPriceChangeNotification>() == _subscriber.Key)  
                {  
                      //if the person who sent the last message is the current subscriber, there is no need to  
                      //publish the message to him, so skip this iteration  
                        continue;  
                }  
                else  
                {  
                       //GetCurrrentClient is a handy method, you can optionally include this    
                       //in your callbacks just to let your clients know who exactly sent the publication  
                        _subscriber.Key.PriceChangeCallback(e.Item, e.Price, e.Change, GetCurrentClient());  
                }  
             }  
         }  

or distinguish your clients based on their usernames, which you should ideally have in your databse as well:

 lock (subscribers)  
            {  
                foreach (var _subscriber in subscribers)  
                {  
                    if(_subscriber.Value == "Jimmy86"))  
                    {  
                        //Identify a specific client by their username and don't send the notification to him  
                        //here we send the notification to everyone but jimmy86  
                        continue;  
                    }  
                    else  
                    {  
                        _subscriber.Key.PriceChangeCallback(e.Item, e.Price, e.Change, GetCurrentClient());  
                    }  
                }  
            }  

Best regards,
Lan Huang

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