c#: make a 3rd party object serializable

Question

On my own object I can add the metatag [Serializable] to make it serializable. Now I use a 3rd party library that I need to be serializable. I inspected the code and it should not be a problem. Is there a way to fix this without altering the 3rd party code?

Answer 1

My advice would be: serialize data, not implementation. The fact of the existence of a 3rd-party object is nothing to do with the data; that is an implementation detail. As such, I always offer the same advice: if serialization ever gets complex, the first thing to do is to introduce a separate DTO model that represents the data in isolation of the implementation, and just map the current state to that DTO. This allows you to handle implementation changes without impact on the storage, and allows otherwise non-serializable objects to be serialized.

Some serializers offer workarounds - for example with protobuf-net you can a: supply the serialization information for any type at runtime, and b: supply a "surrogate" to use automatically when it gets tricky, but - using a DTO model is simpler and easier to maintain.

Your use of [Serializable] suggests BinaryFormatter; in my opinion, this is almost never a good choice for any kind of storage, since BinaryFormatter relies on implementation details. It works nicely for passing data between two in-sync app-domains, though