c# - Force XML serialization of XmlDefaultValue values

Question

Using a C# class generated from an XSD document, I can create an object, and serialize it successfully. However, some attributes have an XmlDefaultValue defined. If any objects have the default value, then those attributes do not get created when the object is serialized.

This is expected behavior according to the documentation. But this is not how I want it to behave. I need to have all such attributes generated in the XML document.
I've checked for any code attributes that can be applied that might force it to be outputted, even if it is the default value, but I couldn't find anything like that.

Is there any way to make that work?

Answer 1

The last answer regarding DataContract is NOT the answer. The XSD is generated automatically and the person consuming the classes is not in control of the attributes used by the original author. The question was about auto-generated classes based on an XSD.

The other answer is problematic too because properties that have defaults defined also may not allow null values (this happens often). The only real solution is to have a serializer where you can tell it what properties to ignore with respect to serialization. This has been and always be a serious problem with current XML serializers that simply don't allow one to pass in what properties to force being serialized.

Actual scenario:

A REST service accepts XML in the body to update an object. The XML has an XSD defined by the author of the rest service. The current object stored by the rest service has a non-default value set. The users modifies the XML to change it back to the default... but the serialized version put in the body of the REST post skips the value and doesn't include it because its set to a default value.

What a quagmire... can't update the value because the logic behind not exporting default values completely ignores the idea that XML can be used to update an object, not just create new ones based on the XML. I can't believe its been this many years and nobody modified XML serializers to handle this basic scenario with ease.