Inherit from abstract class in WCF without exposing that class

问题

I have various classes which I want to expose as Complex Types in WCF, so I add [DataContract] and [DataMember] attributes as necessary on those types and properties.

However if I want to have them inherit from an abstract base class (for example Person inherits from abstract EntityBase), I get an error that the type "cannot inherit from a type that is not marked with DataContractAttribute or SerializableAttribute".

The problem is, if I add [DataContract] attribute to the base class, then that base class is exposed to the client via the WSDL. Not a huge deal I guess, but I would prefer my client doesn't know about my internal implementation.

If I add the [Serializable] attribute to the base class, then it seemed to work at first (it could be serialized but EntityBase was not referenced in the WSDL), but now if I add any properties to EntityBase then it will also complain that its properties are not serializable. (For example I add an ICollection then I get an error that RuleViolation is not serializable).

Unfortunately there seems to be no analogue to [IgnoreDataMember] for a [Serializable] type ([NonSerialized applies only to fields, not properties).

So basically I want to declare this base type but don't need any of its members to be serialized; is there any way to set this up in WCF so the client doesn't see this base type?

回答1:

Did you try not marking your entities with [DataContract] and [DataMember] at all (so that default serialization is used) and instead marking base class properties with [IgnoreDataMember]?

You always have several choices and I'm afraid you will not like any of them.

• Create a set of DTO objects and convert entities to DTO. This is generally a best practice if you want to hide your inner implementation.
• Create a surrogate class (implement IDataContractSuroggate) for each entity so that you have control over serialization - I'm not sure if this avoids the problem.
• Upgrade to .NET 4.0 and use EF with POCO classes (with no EntityBase as parent)

Best regards, Ladislav

回答2:

I think you have to use the KnownType attribute. For instance see WCF issues with KnownType for Dictionary

[EDIT] A more complete discussion of this problem and its solution can be found here: WCF: Interfaces, Generics and ServiceKnownType

来源：https://stackoverflow.com/questions/3496952/inherit-from-abstract-class-in-wcf-without-exposing-that-class