Hi

In some of my DataContracts I have some custom properties that gives me an SerializationException when serialized. I use the same DataContracts (assembly)on both service and client.

The message sounds something like: "Type 'CustomerContract' in assembly 'DataContracts' is not marked as serializeable"

An example of my DataContract that gives my the exception:

[DataContract]

public class CustomerContract : IExtensibleDataObject

{

private int invoiceItemAggregateOption;

[DataMember]

[DerivedAttribute("Customer.InvoiceItemAggregateOption")]

public int InvoiceItemAggregateOption

{

get {}

set {}

}

}

DataContracts that does not have the "DerivedAttribute" attribute works as a charm, so I guess this is the reason I get this SerializationException.

When using the SvcUtil.exe/VS 2008 autogenerated proxy client custom attributes work work very well. It all started when I started to use ChannelFactory and shared assemblies.

So my question is: Is it possible to use custom attributes on DataContracts? And how?

Hi,

Have you marked your custom attribute with [Serializable]? Actually it works fine here - both
with and without it, so it might be something else. ( ChannelFactory / Shared assembly scenario ).


--larsw

I tried to mark the attribute with [Serializable] but it didn't make any difference. That makes sense if it doesn't matter as you said, it works fine for you with and without.

Then I tried to set [Serializable] for every contract inits inherited contracts likethis:

[DataContract]

[Serializable]

public class CustomerContract : EntityContract, IExtensibleDataObject

{

}

[DataContract]

[Serializable]

public class EntityContract : IExtensibleDataObject

{

}

After this I got a new message:

Type System.Runtime.Serialization.ExtensionDataObject in the assembly System.Runtime.Serialization, version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089 is not marked as serializable.

As you can see this is not aclass that I have control over, because its in the System.Runtime.Serialization assembly, and its not serializable. Is it wrong to make my datacontracts implement this interface? I have commed a step further, but not reached the goal yet... Anyone?

YOu can use IExtensibleDataObject but you will need to add a reference to the assembly. Also when derviing from a class, make sure to add teh [KnownType(typeof(baseClassName))] attribute to the new class so that the wsdl generation can correctly pick up the base class members.

Should I use the KnownType attribute for every subclass in the inheritance hierarchy or just the lowest base class?

Eg:

public class CustomerContract : ActorContract, IExtensibleDataObject

{

}

public class ActorContract : EntityContract, IExtensibleDataObject

{

}

public class EntityContract : IExtensibleDataObject

{

// Implements the IExtensibleDataObject interface

}

Should this declare the CustomerContract with the only known type EntityContractlike this:

[DataContract]

[Serializable]

[KnownType(typeof(EntityContract))]

public class CustomerContract : ActorContract, IExtensibleDataObject

{

}

Yes, sothat the wsdl can generate the correct properties.

Sorry that I'm not sure what you said yes to. I asked you a twofolded question, sorry for that.

To make the question a bit clearer:

Should I declare every inherited class as a known type like this:

1)

[DataContract]

[Serializable]

[KnownType(typeof(ActorContract))]

[KnownType(typeof(EntityContract))]

public class CustomerContract : ActorContract, IExtensibleDataObject

{

}

or just like this:

2)

[DataContract]

[Serializable]

[KnownType(typeof(EntityContract))]

public class CustomerContract : ActorContract, IExtensibleDataObject

{

}

Which is the correct way? 1 or 2?

Again, sorry being so daft...

The first way. You want to make sure that the metadata gets all that it needs.

I did what you said, but now it's the ExtensionDataObject that is the problem. My base contract implements the interface IExtensionDataObject:

[DataContract]

[Serializable]

public class EntityContract : IExtensibleDataObject

{

#region IExtensibleDataObject Members

private ExtensionDataObject extensionData;

public ExtensionDataObject ExtensionData

{

get { return extensionData; }

set { extensionData = value; }

}

#endregion

}

I get this error message:

System.Runtime.Serialization.SerializationException: Type 'System.Runtime.Serialization.ExtensionDataObject' in Assembly 'System.Runtime.Serialization, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' is not marked as serializable.

As you can see in the code snippet above I have implemented it in the base class and it is in a assembly that I have no control over. Why this message?

I did what you said, but now it's the ExtensionDataObject that is the problem. My base contract implements the interface IExtensionDataObject:

[DataContract]

[Serializable]

public class EntityContract : IExtensibleDataObject

{

#region IExtensibleDataObject Members

private ExtensionDataObject extensionData;

public ExtensionDataObject ExtensionData

{

get { return extensionData; }

set { extensionData = value; }

}

#endregion

}

I get this error message:

System.Runtime.Serialization.SerializationException: Type 'System.Runtime.Serialization.ExtensionDataObject' in Assembly 'System.Runtime.Serialization, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' is not marked as serializable.

As you can see in the code snippet above I have implemented it in the base class and it is in a assembly that I have no control over. Why this message?

Hi,

Are you really sure you use the DataContractSerializer and not the XmlSerializer?

--larsw

How do I know that? I mean, I create DataContract classes and tag them with the tag [DataContract]. What else could I do or should not do? As you can read I'm not that sure, but I think I use the right serializer here. How can I find this out for sure?