Exposing Member Functions in a Custom Class through WCF

I have some member functions in three custom classes already created in my service. My objective is to use these custom classes on the client side to access the the member functions in the service. How do I expose these classes with all the member methods in them to the client?

I created these three classes in my service and marked them as "DataContract", and the member functions as "OperationContract". I created an Interface that defines these custom classes as OperationContracts returning an object of each of the classes through implementing them on a separate class.

Unfortunately, I couldn't achieve my objective because two of the classes have a constructor that takes some parameters, whereas the class with no constructor was accessible on the client side but I couldn't see the member methods in the class.

I need your hints on what to d开发者_如何学JAVAo.

That won't be easy to do. One way would be to share the DataContract-decorated types between the WCF server and its clients, i.e. add a reference to your service assembly in the client project and bind the service reference to that assembly reference.

However, that breaks contract implementation independence, as the exact same service assembly will need to exist on both the client and the server, and be kept synchronized every time it changes.

See here for more details.

By default and by design, WCF will only share contracts between client and server, e.g. your services ([ServiceContract]), their methods ([OperationContract]) and the data structures they operate on ([DataContract]).

WCF is a message passing system, so all the client and the server share in terms of the data being passed around is a XML serialized message format. When you add a service reference, the client-side proxy will generate a class for each [DataContract] that will look identical in XML serialized format - only the data is being moved back and forth - no behavior (no methods).

Basically, if you want to expose functionality, you need to have a service method decorated with a [OperationContract] attribute. Methods on your data classes will never be visible to the client - and that's by design.

If you control both ends of the communication and both are .NET based, you can "trick" your way around this limitation:

• put all your service and data contracts into a separate class library assembly
• use a reference to that common, shared assembly to create your service
• before you do an Add Service Reference, add a reference to that common assembly on your client

In that case, the WCF runtime will reuse existing types from that common assembly, instead of re-creating them from the service description. And since that assembly contains the shared code that the server also uses, your classes also have their methods present.

It works ok in a .NET only scenario, but it's really kind of a dirty trick behind the proper service separation facade.