Howto ignore unknown types with DataContractSerializer
问题 I try to use DataContractSerializer in my application in order to be backward and forward compatible and to support round trip (if possible). Is it possible to support round trip, or if not, is it possible to just ignore unknown types in the following scenario? Suppose I have a class ClassWithObject that has a property of type object and the older version of my application stored an object of type CurrentAdditionalData in this property. [DataContract] [KnownType(typeof(CurrentAdditionalData))