Deserialize when I don't know the class

[flycast]

I have two classes that both inherit from the same base class. I will be deserializing objects from XML text files. How do I tell what class the objected represented in the text file is so I can deserialize into the right instance of class?

I developed the code below using the base class. I now actually have two classes that inherit the Robot class.

        If File.Exists(fullPath) Then
            Dim rbt As New Robot
            Dim reader As New System.Xml.Serialization.XmlSerializer(GetType(Robot))
            Dim file As New System.IO.StreamReader(fullPath)
            rbt = CType(reader.Deserialize(file), Robot)
            file.Close()
            Return rbt
        Else
            Return Nothing
        End If