Recently I needed to serialize abstract classes in WCF.
The best way to explain it is with an example.
I have a abstract class
[KnownType(typeof(CreditCardPayment))]
public abstract class Payment
{
private string _amount;
private string _currency;
[DataMember]
public string currency
{
get { return _currency; }
set { _currency = value; }
}
[DataMember]
public string amount
{
get { return _amount; }
set { _amount = value; }
}
}
The class deriving it is
[DataContract]
public class CreditCardPayment:Payment
{
private string _creditCardNumber;
private DateTime _expiryDate;
private string _securityCode;
[DataMember]
public string securityCode
{
get { return _securityCode; }
set { _securityCode = value; }
}
[DataMember]
public DateTime expiryDate
{
get { return _expiryDate; }
set { _expiryDate = value; }
}
[DataMember]
public string creditCardNumber
{
get { return _creditCardNumber; }
set { _creditCardNumber = value; }
}
}
When I attempted to serialize this to a message queue, I got the error below
at Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationWriterAirTimeOrder.Write3_Payment(String n, String ns, Payment o, Boolean isNullable, Boolean needType)
at Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationWriterAirTimeOrder.Write5_AirTimeOrder(String n, String ns, AirTimeOrder o, Boolean isNullable, Boolean needType)
at Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationWriterAirTimeOrder.Write6_AirTimeOrder(Object o)
The solution is to the code below
[DataContract(Namespace = "www.pro.com")]
[KnownType(typeof(CreditCardPayment))]
[System.Xml.Serialization.XmlInclude(typeof(CreditCardPayment))]
public abstract class Payment
{
private string _amount;
private string _currency;
[DataMember]
public string currency
{
get { return _currency; }
set { _currency = value; }
}
-------------------------------------------------------------------------------
Tuesday, May 27, 2008 1:59 PM