Expand|Select|Wrap|Line Numbers
- interface IPersistable;
- [Serializable()]
- [XmlInclude(typeof(Task))]
- abstract class PersistableObject : IPersistable;
- [Serializable()]
- [XmlInclude(typeof(AccountExpirationWarningTask))]
- [XmlInclude(typeof(EnableAccountTask))]
- abstract class Task : PersistableObject;
- [Serializable()]
- class EnableAccountTask : Task;
- [Serializable()]
- class AccountExpirationWarningTask : Task;
I have been using XML serialization with these classes for some time without any problems and have only just implemented binary serialization. The binary serialization implementation required the addition of the IPersistable interface (which did not exist previously) and the Serialization() attribute on each class. XML serialization worked perfectly prior to these additions.
After making these modifications, binary serialization works perfectly but XML serialization appears to be broken. When attempting to XML serialize an array of PersistableObject[] containing instances of AccountExpirationWarningTask and/or EnableAccountTask, the following exception is thrown:
Expand|Select|Wrap|Line Numbers
- System.InvalidOperationException: There was an error generating the XML document. ---> System.InvalidOperationException: The type Task was not expected. Use the XmlInclude or SoapInclude attribute to specify types that are not known statically.
My XML serialization code is as follows:
Expand|Select|Wrap|Line Numbers
- private bool Commit(PersistableObject[] objects)
- {
- System.IO.MemoryStream stream =
- new System.IO.MemoryStream();
- System.Xml.Serialization.XmlRootAttribute xmlRoot =
- new System.Xml.Serialization.XmlRootAttribute();
- xmlRoot.ElementName = "ObjectList";
- System.Xml.Serialization.XmlSerializer serializer =
- new System.Xml.Serialization.XmlSerializer(typeof(PersistableObject[]), xmlRoot);
- serializer.Serialize(stream, objects);
- ...
- }
The application performs binary serialization prior to XML serialization, however XML serialization still fails if I attempt to perform XML serialization first.
Does anyone have any ideas what might cause this problem? I'm quite stuck.