WCF, Exceptions & Inheritance

More than halfway through the web-service project I am currently working at, my customer decided to inform me just now that I can't ever throw exceptions to client applications. The question is that until now I was throwing FaultException exceptions everytime there was a validation, database or any other kind of error. I will clearly need to change this behavior without further questions, but the problem is that I don't really know what to replace it for. The service has 4-5 endpoints which return different DataContract structures, so I thought about designing a base class having a boolean (indicating failure or success) and object (which I would use to send the serialized exceptions if the开发者_高级运维y are to be thrown) fields and make all the other DataContracts inherit from this structure. But I am not really sure this is the best option. What do you advise me to do?

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This requirement is probably due to the fact that Silverlight consumers are supposed to access the service which can't handle those exceptions in a proper way unless they switch to the http client stack (which comes with its own drawbacks).

We've solved the problem by including a Fault out parameter in every service method signature that needs to be checked by the client. It really sounds worse than it is in practice.

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This will work for sure for service operations that return something. So if you only have that kind of operations use it like you proposed: try catch in the service operation and wrap the exception in the returned data contract.

What about the service operations that have a void return type? You could also try catch but how do you return the status/error to the client? Are you gonna hev this scenario in your app?