How to exclude a class from the XML serialization assembly

Question

I have a C# project where I have to activate XML serialization assembly generation (GenerateSerializationAssemblies in csproj).

The project contains a class that is derived from System.ComponentModel.Composition.ExportAttribute.

[AttributeUsage(AttributeTargets.Class, AllowMultiple = true, Inherited = false)]
public class MyExportAttribute : ExportAttribute
{ ... }

The compiler fails with an error complaining about a missing public property setter on ExportAttribute.ContractName:

Error 10 Cannot deserialize type 'System.ComponentModel.Composition.ExportAttribute' because it contains property 'ContractName' which has no public setter.

Actually I do not want to serialize this class, so I'd like to exclude it from the serialization assembly. Can I do that? Or alternatively, specify which classes to include?

What I've tried / thought of so far:

Hide the ContractName property (non virtual) in MyExportAttribute with an empty setter, call the base implementation in the getter -> same error, serializer still wants to access the properties on the base class
Applying XmlIgnore to that MyExportAttribute.ContractName did not help either
Moving classes to other projects is an option, but I'd like to avoid that if possible
XmlIgnore on the ContractName property would solve my problem, but of course I cannot add it to ExportAttribute. Is there a similar XML serialization control attribute that can be applied to a class, so that it's ignored by the serializer?

I currently see two options: a) explicitly specify the types you want to be included in the serialization assembly using the `/t`switch of [`sgen.exe`](https://msdn.microsoft.com/en-us/library/bk3w6240(v=vs.110).aspx), or b) move the type(s) that you don't want to include to another assembly. I'm not aware of any attributes that would exclude the type from the generated code. -- Or, another option that you have is to have a look at [XGenPlus](http://www.codeproject.com/Articles/21278/XGenPlus-A-Flexible-Tool-to-Generate-Typed-XML-Ser) — Dirk Vollmar, Aug 25 '16 at 10:57
Thanks, option a) is something I was looking for. If I'm right I cannot do this in conjunction with the GenerateSerializationAssemblies csproj element, but I can add the sgen command line as a postbuild action. — dzs, Aug 26 '16 at 11:31

score 1 · Accepted Answer · answered Feb 18 '19 at 16:59

To work around this error, I implemented IXmlSerializable on the class that gave sgen issues. I implemented each required member by throwing NotImplementedException:

[AttributeUsage(AttributeTargets.Class, AllowMultiple = true, Inherited = false)]
public class MyExportAttribute
    : ExportAttribute
    // Necessary to prevent sgen.exe from exploding since we are
    // a public type with a parameterless constructor.
    , System.Xml.Serialization.IXmlSerializable
{
    System.Xml.Schema.XmlSchema System.Xml.Serialization.IXmlSerializable.GetSchema() => throw new NotImplementedException("Not serializable");
    void System.Xml.Serialization.IXmlSerializable.ReadXml(System.Xml.XmlReader reader) => throw new NotImplementedException("Not serializable");
    void System.Xml.Serialization.IXmlSerializable.WriteXml(System.Xml.XmlWriter writer) => throw new NotImplementedException("Not serializable");
}

How to exclude a class from the XML serialization assembly

1 Answers1