Question

I have an inherited code base that was developed in .NET 1.1. When I migrated it to 2.0, I renamed an assembly. Now, I find that it will be necessary to read old files containing objects serialized by the old assembly and .NET 1.1. Some fields are successfully deserialized, but most are ignored. If I enable FormatterAssemblyStyle.Full , I get an error such as:

Member ‘T_VERSION+s_sys_ver‘ in class ‘MyNamespace.T_VERSION‘ is not present in the serialized stream and is not marked with System.Runtime.Serialization.OptionalFieldAttribute.

An examination of the binary file shows that T_VERSION+s_sys_ver is present in some form, and the field type hasn’t changed.

Is there any way to deserialize the old format files short of manually reverse engineering the old format and writing my own manual deserialization routine?

Answer 1

Check SerializationBinder

During serialization, a formatter
transmits the information required to
create an instance of an object of the
correct type and version. This
information generally includes the
full type name and assembly name of
the object. The assembly name includes
the name, version, and strong name
(see Strong-Named Assemblies) hash of
the assembly. By default,
deserialization uses this information
to create an instance of an identical
object (with the exception of any
assembly loading restricted by the
security policy). Some users need to
control which class to load, either
because the class has moved between
assemblies or a different version of
the class is required on the server
and client.