xsi:type and inherited classes

[chr]

Hi I refer to an archived discussion titled inherited classes and xml.serialization

I seem to have the same situation, i have two classes B and C inheriting class A, class A includes both types B and C as seen below

<System.Xml.Serialization.XmlIncludeAttribute(GetT ype(B)), _
System.Xml.Serialization.XmlIncludeAttribute(GetTy pe(C))> _
Public MustInherit Class A
.....
end class

Problem is when i create an instance of class B and serialise it using XmlSerializer, the xsi:type is still missing and this is giving me an error when it comes to submitting the generated XML file as a request to a webservice.I want it to show <A xsi:type="B">

Can someone please guide me in the right direction or point out to me what im doing wrong?

Your help would be greatly appreciated

Thanks

[jkmyoung]

I think you would have to explicitly cast it as a type B before you serialize it. If you're serializing as a class A, then it will only include type A details, leaving out anything from class B.

I'm not sure if this is what you're looking for.

[chr]

I think you would have to explicitly cast it as a type B before you serialize it. If you're serializing as a class A, then it will only include type A details, leaving out anything from class B.

I'm not sure if this is what you're looking for.

The details im serializing are fine i.e. those of type B my only problem is "xsi:type=" not being included in my output xml file. Any ideas please?

[jkmyoung]

Which method of serialize are you using, eg what object is the output going to?
Is it an XmlWriter? If so, could you post your code on how you set up the XmlWriter?

[chr]

I am outputting to a Text Writer

this is the code

 
   Dim serializer As New XmlSerializer(RQ.GetType)
   Dim writer As TextWriter
   Dim strFileName As String
 
   strFileName = Server.MapPath("xml") & "\request_" & Session.SessionID.ToString & ".xml"
        writer = New StreamWriter(strFileName)
        serializer.Serialize(writer, RQ)
        writer.Close()
 
 

now RQ is an instance of a class (which was auto generated using xsd tool and given schema) and one of its attributes is an instance of Class B mentioned above which inherits from class A. Is this what u are asking for?

[chr]

One thing i am wondering about is whether this is happening because the attribute in class RQ is actually of type B not of type A. Could this be? however when i change it to type A and i try to serialise i get the following error

The type namespace.B was not expected. Use the XmlInclude or SoapInclude attribute to specify types that are not known statically.

i've googled this and i have added the xmlinclude over class A but nothing i keep getting the same error. Am i missing out on something?

thanks once again

[jkmyoung]

Not sure, but have you tried using an XmlTextWriter instead?
http://msdn2.microsoft.com/en-us/library/aa335857(VS.71).aspx

[chr]

yep i did but no change its still the same ...

[chr]

ok i found out that the problem is actually because of the new class D. In it it has an attribute of type Class A which i am setting to type class B before serializing

now when i create an instance of class B and serialise it (to type classA) i get <A xsi:type=B> but what i need to do is serialise to type class D and in it get <A xsi:type=B>

Basically my classes are

Class D 
      dim attrB as A -> this should show as <A xsi:type=B>
      other attributes ...
end class 
 
[XmlIncludeAttribute(GetType(B)]
Class A 
  ....
end class 
 
Class B : A 
  ....
end class 

now im getting this error: The type namespace.B was not expected. Use the XmlInclude or SoapInclude attribute to specify types that are not known statically.

But XmlInclude is already included on top of class A .. should it be included elsewhere? :(