Rory Primrose

The exception is question is this:

An unhandled exception of type 'System.ServiceModel.CommunicationException' occurred in mscorlib.dll

Additional information: The underlying connection was closed: The connection was closed unexpectedly.

Anyone got any pointers?

The problem was that because I was using contracts defined in assemblies rather than a WSDL setup, my data contracts were not assigned for the non-primitive values being returned from the service. In this case, I was returning a list of a concrete type, but the type wasn't defined in the contract.

Hi rory,
I have some custom collection object marked with DataContract and when I try to get it through the service at client, it throws the same error that you mentioned. I can see my service filling up custom collection object but then when it goes to the first element of that collection and tries to read the property value, it throws same exception.

Any clues?

Hi Rajiv,

Just to clarify, when you read the first element and an exception is thrown, is that still in the server code or the client code? What kind of class/interface does your custom collection use?

Hi rory,
Thanks for prompt help.

It throws exception in server code and bubbles up at client side.
My custom collection has [CollectionDataContract] attribute and it inherits BindingList and implement IRaiseItemChangedEvents, where T is my custom object.

Thanks
Rajiv

Try turning on tracing and logging on both the server and client. Use the trace viewer in the SDK to read the entries. That might give some background info. The other thing to try is turning on the server config that allows detailed exception information to be passed back to the client.

Thanks for your help.

Tracing and logging really helped. I used WCF sdk tools (viewer and editor for config). I see that I was trying to serialize bitmap property of my object which it was not allowing and somehow gave me the "connection closed" error. Now, I have to find a way to serialize an image field for my object.