Deserialization of changed objects

[Urs Vogel]

Hi

Let's assume that I have an object_V1 (version 1) serialized to disk. Later,
the class for object_V1 will change to object_V2, having some more members.
Now, I would like to read my previously saved objects of type object_V1 into
object_V2, which (logically) now throws an exception.

I tried to make use of the HeaderHandler, but this gives me only access to
the methods, not the members. I also tried to inherit object_V1 into
object_V2, which didn't work either.

Is there an way to control this deserialization process, any samples around?

Any hints ar appreciated.

Thanks. Urs.

[Robert Jacobson]

Are you using basic XML serialization? You should be able to add attributes
to your object_V2 class definition and property definitions that will map
the XML from object_V1 to object_V2.

Controlling XML Serialization Using Attributes
http://msdn.microsoft.com/library/de...attributes.asp
Overriding XML Serialization
http://msdn.microsoft.com/library/de...ridesclass.asp
"Urs Vogel" <ur******@yahoo.com> wrote in message
news:uh**************@TK2MSFTNGP12.phx.gbl...

Hi

Let's assume that I have an object_V1 (version 1) serialized to disk. Later, the class for object_V1 will change to object_V2, having some more members. Now, I would like to read my previously saved objects of type object_V1 into object_V2, which (logically) now throws an exception.

I tried to make use of the HeaderHandler, but this gives me only access to
the methods, not the members. I also tried to inherit object_V1 into
object_V2, which didn't work either.

Is there an way to control this deserialization process, any samples around?
Any hints ar appreciated.

Thanks. Urs.

[Sahil Malik]

You would have to implement ISerializable in Object_V2.

Object_V2, GetObjectData - would serialize, and the protected
new(Serialization Info, StreamingContext context) would deserialize (hope my
memory is holding up to the exact param list ... it's been a while since I
did this.

So the V2 - V1 members would get a default value assignment in this New
function.

_ Sahil Malik
Independent Consultant.
"Urs Vogel" <ur******@yahoo.com> wrote in message
news:uh**************@TK2MSFTNGP12.phx.gbl...

Hi

Let's assume that I have an object_V1 (version 1) serialized to disk. Later, the class for object_V1 will change to object_V2, having some more members. Now, I would like to read my previously saved objects of type object_V1 into object_V2, which (logically) now throws an exception.

I tried to make use of the HeaderHandler, but this gives me only access to
the methods, not the members. I also tried to inherit object_V1 into
object_V2, which didn't work either.

Is there an way to control this deserialization process, any samples around?
Any hints ar appreciated.

Thanks. Urs.

[Sahil Malik]

You would have to implement ISerializable in Object_V2.

Object_V2, GetObjectData - would serialize, and the protected
new(Serialization Info, StreamingContext context) would deserialize (hope my
memory is holding up to the exact param list ... it's been a while since I
did this.

So the V2 - V1 members would get a default value assignment in this New
function.

_ Sahil Malik
Independent Consultant.
"Urs Vogel" <ur******@yahoo.com> wrote in message
news:uh**************@TK2MSFTNGP12.phx.gbl...

Hi

Let's assume that I have an object_V1 (version 1) serialized to disk. Later, the class for object_V1 will change to object_V2, having some more members. Now, I would like to read my previously saved objects of type object_V1 into object_V2, which (logically) now throws an exception.

I tried to make use of the HeaderHandler, but this gives me only access to
the methods, not the members. I also tried to inherit object_V1 into
object_V2, which didn't work either.

Is there an way to control this deserialization process, any samples around?
Any hints ar appreciated.

Thanks. Urs.