WCF service is failing for Operations returning Entity classes

Question

User-758219241 posted

My database is having following table

Country >> CountryId, Country

Following is the exact architecture in my application.

Geography_EF >> Entity framework project (using EF 5) Geography_Model >> Model generated from EF (in short, entity classes). This contains Country class. Geography_WCF >> WCF application containing various service contracts.

The issue is that when I write an operation contract returning Country object (or collection) it gives me an error saying "The underlying connection is closed. "The underlying connection was closed: The connection was closed unexpectedly." Here, I can see the call gets completed to this operation contract and immediately this exception occurs.

whereas if I write an operation to return a specific field only (i.e. CountryId or Country table) then it works fine.

I am using repository pattern and Unity container as well.

What do you think, I am missing?

Answer 1

User-1000095884 posted

Hi,

The issue may caused by WCF was unable to serialize the circular reference that Entity Framework created when loading the referenced entities, try put DataContract(IsReference = true)] above your model class. For details refer:

<!--EndFragment-->http://www.binaryforge-software.com/wpblog/?p=129

If the issue still exists, suggest you enable tracing for your service to help to dignose the actual issue.

Best Regards.

Answer 2

User614805505 posted

Hi,

You have to detach the returning entity object from context before sending via WCF.

http://msdn.microsoft.com/en-us/library/system.servicemodel.domainservices.client.entityset.detach(v=vs.91).aspx