Detect socket disconnect in WCF

问题

We're building a WCF server (.NET 4.0). It will only use net.tcp transport.

When a client closes the TCP connection, the server gets unhandled CommunicationException, and terminates.

Q1. How do I handle the CommunicationException so the server does not terminate and continues serving other clients?

Q2. In the handler, how do I get SessionId of the session that was aborted? I need this to do clean up some session-specific data.

Thanks in advance!

P.S. The connection is over the Internet, so the socket may be closed anytime, regardless on whether the client disconnects gracefully, or not.

回答1:

Any WCF channel implements ICommunicationObject , which provides events for the channel lifetime.

You should listen to the Faulted event

The sessionId can be accessed as always from the OperationContext.Current property.

When your client open the channel (on the first operation), register to the adequate events:

OperationContext.Current.Channel.Faulted += new EventHandler(Channel_Faulted);
OperationContext.Current.Channel.Closed += new EventHandler(Channel_Faulted);

and:

 void Channel_Faulted(object sender, EventArgs e)
 {
     Logout((IContextChannel)sender);
 }

 protected void Logout(IContextChannel channel)
 {
        string sessionId = null;

        if (channel != null)
        {
            sessionId = channel.SessionId;
        }
      [...]
 }

回答2:

ICommunicationObject obj = (ICommunicationObject)callback;
                obj.Closed += new EventHandler((a, b) => 
                {
                    if (list.Exists(cli => cli.CallbackService == (ITecnobelRemoteServiceCallback)a))
                    {
                        var query = (from cc in list where cc.CallbackService == (ITecnobelRemoteServiceCallback)a select cc).ToList();
                        query.ForEach(
                            delegate (Client ccc)
                            {
                                ccc.CallbackService = null;
                            });
                    }

                });

来源：https://stackoverflow.com/questions/5338842/detect-socket-disconnect-in-wcf