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WCF Duplex Contract GetCallbackChannel problem

Posted By:      Posted Date: December 04, 2010    Points: 0   Category :WCF
 

My basic set up is as follows:

  • service is set up to have a duplex contract between the client and server.
  • Server can only have one client connected at a time, once a client connects, the server locks to deny new connections.

Every thing works as expected unless a client does not properly disconnect. So to solve this, I have included a timer on the server, to "ping" the client every 2 seconds. If the method throws an exception, the client is not connected anymore, and the server will unlock to allow a new connection.

My problem is that the OperationContext.Current.GetCallbackChannel<T>  method always returns a null reference and throws an exception in my Tick method regardless of whether or not a client is connected because I am using it in a method that was not invoked by the client.

I know my current set up does work because I can call other "duplexed" methods in methods the the client invokes server side, and the OperationContext.Current.GetCallbackChannel works as expected.

So how do I grab the proper channel to talk back to the client in my timer's tick method? Thanks

 




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Interface:

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using System.ServiceModel;
using System.Text;

namespace WCFDuplexServ
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Interface:

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