XML serialization of objects with envelope in C#

Question

I need to serialize objects to XML in C#. The objects should be wrapped in an envelope. For that, I've created the following Envelope class:

[XmlInclude(typeof(Person))]
public class Envelope
{
    public string SomeValue { get; set; }
    public object WrappedObject { get; set; }
}

I use the following code to serialize the class:

string fileName = ...;
XmlSerializer serializer = new XmlSerializer(typeof(Envelope));
TextWriter textWriter = new StreamWriter(fileName);
try
{
    serializer.Serialize(textWriter, <instance of envelope>);
}
finally
{
    textWriter.Close();
}

When I assign an object of type Person to WrappedObject, I get the following XML:

<Envelope>
    <SomeValue>...</SomeValue>
    <WrappedObject xsi:type="Person">
        ....
    </WrappedObject>
</Envelope>

The problem is, I would like the tag for the wrapped object to be named after the actual class that I pass in. For example, if I assign an instance of Person to WrappedObject, I'd like the XML to look like the following:

<Envelope>
    <SomeValue>...</SomeValue>
    <Person>
        ....
    </Person>
</Envelope>

If I assign an instance of Animal, I'd like to get

<Envelope>
    <SomeValue>...</SomeValue>
    <Animal>
        ....
    </Animal>
</Envelope>

How would I achieve that?

EDIT

Actually I've simplified my example a little... The wrapped object is actually wrapped again:

public class Envelope
{
    public string SomeValue { get; set; }
    public Wrapper Wrap { get; set; }
}

[XmlInclude(typeof(Person))]
public class Wrapper
{
    public object WrappedObject { get; set; }
}

How would I handle this using the attributes override?

Answer 1

You need to use attribute override. I am using it heavily as I do a lot of custom serialisation.

This is a rough untested snippet but should point you in the right direction:

XmlAttributes attributes = new XmlAttributes();
XmlAttributeOverrides xmlAttributeOverrides = new XmlAttributeOverrides();
attributes.XmlElements.Add(new XmlElementAttribute("Person", t));
xmlAttributeOverrides.Add(typeof(Person), "WrappedObject", attributes);
XmlSerializer myserialiser = new XmlSerializer(typeof(Envelope), xmlAttributeOverrides);