Hey,
I am trying to get a WCF service to return a List that contains instances of classes that inherit from A but am getting "The underlying connection unexpectedly closed" when the service returns the list.
I have the following
[DataContract]
[Serializable]
public class A { ... }
[DataContract]
[Serializable]
public class B : A { ... }
[DataContract]
[Serializable]
public class C : A { ... }
I then have a service defined as
[ServiceContract( NameSpace = "Name.Space" )]
public interface I
{
[OperationContract]
List<A> GetList();
}
If I attempt to return a list as follows
List<A> list = new List<A>()
{
new B(),
new C()
}
I get the above error in the proxy class.
If a change the service to return List<B> and just add Bs to it it returns fine, so this leads me to believe it is related to WCF having difficulty with the subtypes.
I have tried adding
[ServiceKnownType( typeof( B ) )]
[ServiceKnownType( typeof( C ) )]
To the class defintion of A, to no avail.
So, is it possible to return a list of subtypes in the same list through WCF?
If so, what am I missing/doing wrong?
Thanks in advance for any assistance you can provide