Object XmlSerialization with protected property setters

Question

Here is my object

    [Serializable()]
    public class PersistentObject
    {
        public virtual int ID {
            get { return id; }
            protected set { id = value;}
        }
        ...
     }

When I try to serialize this to xml, I get an error "The Property or indexer PersistentObject.ID cannot be used in this context because the set accessor is inaccessible" . If the setter doesn't exist, it works fine. I want to keep this ID as serialized without a hacktastic solution that involves an of [XmlIgnore()] on ID. I would prefer if I could add [XmlIgnore()] on just the setter, but the compiler complains. Anybody have a good solution around this?

Answer 1

Unfortunately, no. XmlSerializer has some things that are... irritating. This is one of them. Options:

• use DataContractSerializer (which supports protected etc, but doesn't offer full xml control)
• annotate with [XmlIgnore] - nothing wrong with it
• implement IXmlSerializable - hard work and very easy to get wrong
• take off the setter, and have a separate protected method to set the value
• use the XmlSerializer constructor that lets you specify everything at runtime; lots of work/maintenance, and you need to manually cache the serializer (otherwise it creates lots of dynamic assemblies)

Answer 2

Even though it doesn't directly answer your question, note that you can serialize properties with an internal setter. To do that, you need to pre-generate the XML serialization assembly with Sgen.exe, and declare that assembly as "friend" using the InternalsVisibleTo attribute :

[assembly:InternalsVisibleTo("MyAssembly.XmlSerializers")]