Serialization of derived objects without the xsi:type

Question

I'm having a problem when serializing a Dictionary containing a list of derived objects. The serialized output contains

<BaseAttributes xsi:type="Turbine" Id="1975fe1f-7aa8-4f1d-b768-93ad262800cd">

where I would like the BaseAttributes to be substituted with Turbine and the xsi:type to be non-existing.

<Turbine Id="1975fe1f-7aa8-4f1d-b768-93ad262800cd">

My code in overall looks like the following. I have a class BaseAttributes from which I derive some classes for example the Turbine class. These classes are stored in a dictionary with a List of BaseAttributes. The dictionary is an implemented serializable dictionary. Below is the code in general.

[XmlInclude(typeof(Turbine)), XmlInclude(typeof(Station)), XmlInclude(typeof(Substation))]
public class BaseAttributes {

  [XmlAttribute("Id")]
  public Guid Id;
}



public class Turbine : BaseAttributes {
  private Element windSpeed;
  public Element WindSpeed {
    get { return windSpeed; }
    set { windSpeed = value; }
  }

  public Turbine(float windSpeed){
    this.windSpeed= new Element(windSpeed.ToString(),"ms");
  }
  //used for xmlserilization
  private Turbine(){}
}



public class CollectionOfBaseAttributes {
  public SerilizableUnitsDictionary<DateTime, List<BaseAttributes>> units;
}

[XmlRoot("dictionary")]
public class SerilizableUnitsDictionary<TKey, TValue>
: Dictionary<TKey, TValue>, IXmlSerializable {

  public System.Xml.Schema.XmlSchema GetSchema() {
    return null;
  }

  public void WriteXml(System.Xml.XmlWriter writer) {

    XmlSerializer valueSerializer = new XmlSerializer(typeof(TValue), new XmlRootAttribute("Units"));

    foreach (TKey key in this.Keys) {
    writer.WriteStartElement("TimeStamp");              
    writer.WriteAttributeString("Value", key.ToString());

    TValue value = this[key];
    foreach (TValue value1 in Values) {             
      valueSerializer.Serialize(writer, value1);    
    }

    writer.WriteEndElement();
  }
}

I don't use a DataContractor for the serialization, as I will not be deserializing the XML. I "just" want to create the XML file with attributes.

I have tried to use the XmlElementOverrides, but there is probably something that I just don' understand in the using. Currently I have tried to use it like this:

XmlAttributes attrs = new XmlAttributes();
XmlElementAttribute attr = new XmlElementAttribute();
attr.ElementName = "Turbine";
attr.Type = typeof(Turbine);
attrs.XmlElements.Add(attr);
XmlAttributeOverrides attrOverrides = new XmlAttributeOverrides();
attrOverrides.Add(typeof(CollectionOfBaseAttributes ), "BaseAttributes", attrs);

XmlSerializer xmlSerializer = new XmlSerializer(typeof(CollectionOfBaseAttributes ),attrOverrides);

But no result from that.

Answer 1

Ran into it again today and was disapointed SO didn't have the answer.

If it's a list of objects in a field or a property add this on top:

[XmlArrayItem(Type = typeof(Turbine))]
[XmlArrayItem(Type = typeof(Station))]

...

If it's a single object add:

 [XmlElement(Type = typeof(Turbine))]
 [XmlElement(Type = typeof(Station))]