Silverlight: DataContractSerializer cannot handle read only collection properties

Question

Hey Stackoverflowers :)

For our Silverlight Project (SL4) I'm using a Model which might contain Lists (IList<AnotherModel>). According to good practice and rule CA2227:CollectionPropertiesShouldBeReadOnly the IList properties don't have a public setter. We serialize the Model using the DataContractSerializer which is working. But when I try to deserialize, a SecurityException is thrown by DataContractSerializer's ReadObject(Stream) Method, complaining that the target property (pointing to the IList property) cannot be set due to a missing public setter.

Since the DataContractSerializer is sealed and neither extendable nor flexible so I currently see no chance to add some kind of additional rules which allow to deserialize the ILists using a foreach-loop on Add() method or some other method of transferring the collection items.

I've also tried to dig into DataContractSerializer source (using Reflector) to create a little fork but it looks like i'd have to dig very deep and replicating whole serialization classes doesn't seem to be a viable solution.

Do you see another chance to serialize a List with no public setter using the DataContractSerializer?

Thank you very much in advance for your ideas!

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UPDATE
Solved using XmlSerializer.

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Thomas

Answer 1

Use concrete (mutable) types and give DCS what it wants.

It works well for me (I usually only specify concrete types in DataContractSerializable classes). The entire approach of generic serialization is a wash and comes with cavaets -- pick your battles. Alternatively, use another approach such as ISerializable (uhg).

Answer 2

In our case, we found out that we were not strictly bound to the DataContractSerializer, and interestingly, the XmlSerializer DOES support serialization of read-only ILists! In fact, it even doesn't allow a public setter for the IList interface in this case (cannot deserialize interface property) but (de-)serializing the ILists items works like a charm.

Only change for us was adding [XmlInclude] attributes in addition to [KnownType] (and of course, replacing the few lines from DataContractSerializer.WriteObject(...) to XmlSerializer.Serialize(...).

Thanks for your support! =)