Question

I have the problem when sequentially serialize-deserialize-serialize a TestClass:

[Serializable]
public class TestClass
{
    public TestClass() { }
    public Foo Foo { get; set; }
}

[XmlInclude(typeof(Bar))]
[Serializable]
public abstract class Foo
{
    [XmlAnyAttribute]
    public List<XmlAttribute> AnyAttr;
}

[Serializable]
public class Bar : Foo
{
}

void Test()
{
  var test = new TestClass { Foo = new Bar() };
  Console.WriteLine(test.Foo.AnyAttr == null);//true

  var firstXml = Helper.SerializeToXml(test);
  Console.WriteLine(Regex.Matches(firstXml, "xsi:type=").Count);//1

  var deserialiezedObject = Helper.DeserializeFromXml<TestClass>(firstXml);
  Console.WriteLine(deserialiezedObject.Foo.AnyAttr.Count);//1
  Console.WriteLine(deserialiezedObject.Foo.AnyAttr[0].Name);//xsi:type

  var secondXml = Helper.SerializeToXml(deserialiezedObject);
  Console.WriteLine(Regex.Matches(secondXml, "xsi:type=").Count);//2

 //var secondDeserialiezedObject = Helper.DeserializeFromXml<TestClass>(secondXml); //InvalidOperationException
    }

full sample

As you can see the deserialization fills the AnyAttr array( by one element – “xsi:type”).

The strange thing happens after we serialize the deserialiezedObject. It produces the “xsi:type” twice in Foo tag.

Is this a XmlSerializer bug or I should manage (delete “xsi:type” from the AnyAttr after deserialization, for instance) the AnyAttr myself some way?

I have a bunch of auto generated classes which contain the AnyAttr field.

Could you suggest how to serialize objects like this without “xsi:type” duplication?

Answer 1

Didn’t find better solution than just deleting “xsi:type” from the AnyAttr (through reflection) after every deserialization