Serializing a reference to a static readonly member

Question

I have a piece of code that looks something like this:

public static class MyStaticClass
{
    public static readonly MyObject1 object1 = new MyObject1();
}

[Serializable]
public class MyOtherClass
{
    public MyObject1 Obj { get; } = MyStaticClass.object1;
}

When deserializing (using default binary serialization) an instance of MyOtherClass, Obj is no longer the same object as MyStaticClass.object1. Is there any way to automatically retain that reference, or am I simply going to have to reconstruct it via a string or some other identifier? If so, what would be the recommended way to cleanly rebuild that reference?

Yes, use [`IObjectReference.GetRealObject()`](https://msdn.microsoft.com/en-us/library/system.runtime.serialization.iobjectreference.getrealobject(v=vs.110).aspx). An example of doing just this is shown in the [docs](https://msdn.microsoft.com/en-us/library/system.runtime.serialization.iobjectreference.getrealobject(v=vs.110).aspx#Anchor_3). — dbc, Sep 29 '16 at 04:27
*default binary serialization* means `BinaryFormatter`, right? — dbc, Sep 29 '16 at 04:29
Related: [How to serialize & deserialize static reference object?](https://stackoverflow.com/questions/32375207/how-to-serialize-deserialize-static-reference-object/32509817#32509817) and [hooking into the deserialization process](https://stackoverflow.com/questions/12692860/hooking-into-the-deserialization-process). — dbc, Sep 29 '16 at 04:35
Yeah, I'm just using `BinaryFormatter` for now. Thank you, I'll look into that interface. — Tom Warner, Sep 29 '16 at 04:48

score 0 · Accepted Answer · answered Sep 29 '16 at 04:28

Is there any way to automatically retain that reference

That depends on your definition of "automatically", but assuming you mean "without writing any additional code", the answer is "no".

Serialization deals with data, not objects. When you deserialize the object, all that the stock deserialization implementations know is the data that was stored. Which is as it should be; a general-purpose deserialization implementation wouldn't even know where to look to match an object like that and use an existing reference, so it'd have to search the entire in-memory object graph from all roots.

You will need to provide a mechanism to deal with this explicitly. Depending on what serialization method you're using, you may be able to customize the entire process so that you don't have to serialize the entire MyObject1 data, but instead just store some kind of marker that your customized deserialization can use to signify the original object.

Alternatively, your customization could just rely on MyObject1 implementing some type of equality, so that you can compare the deserialized object and replace its reference with the "stock" reference if the two objects are equal.

If you're using a serialization method that supports the IObjectReference.GetRealObject() mentioned in the comments, that would work too.

But whatever you do, you're going to have to do it yourself. (Or use a third-party library that supports a feature like that out of the box…I'm not aware of any, but that doesn't mean it doesn't exist.)

My current best idea to to just store a marker like like you said, and have a method in `MyStaticClass` that parses that marker to return the correct object. Thanks for your input! — Tom Warner, Sep 29 '16 at 04:47

Serializing a reference to a static readonly member

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