Deserializing xml with dynamically loaded assembly

Question

Hello,

I have a problem with xml-deserialization and dynamically loaded assemblys. I load my assembly directly from a zip-file to a byte array. Then i load this assembly. The assembly contains a data-model, which should be deserialized with XmlSerializer. The problem is that I always get an TypeInitializationException, if i try to load my xml.

The german exception is following:

System.InvalidOperationException: Fehler im XML-Dokument (62,13). ---> System.TypeInitializationException: Der Typeninitialisierer für "Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationReaderOrder" hat eine Ausnahme verursacht. ---> System.NullReferenceException: Der Objektverweis wurde nicht auf eine Objektinstanz festgelegt.

bei Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationReaderOrder..cctor()

If i load my dll directly from a dll-file, and not from a zip into a byte-array, the xml could be sucessfully deserialized.

I the internet i found, that the problem could be Lists with own types, but the solutions i found there didn't solve my problem.

It would be great, if somebody could help me.

Thanks, Martin

EDIT:

I've found that I couldn't use generic Lists with own types, if I load the assembly via byte-array, as it is written on other website. I couldn't say, why I first hadn't success with this solutions, but after a second try it works. I've made a workaround with ArrayList, but im very unhappy with this. Is there a better solution, where I can use generic lists? Or if there isn't a better solution, is there a better Serializer/Deserializer for XML?

Answer 1

I got around this by using sgen to create serialization assemblies (*.XmlSerializers.dll) for each assembly that contained types I want to serialize and including them with my app whenever I do any XmlSerialization. Then make sure they exist in your bin path at runtime. XmlSerialization probes for the *.XmlSerializers.dll and uses these serialization types instead of creating them at runtime.

Answer 2

what you get when you load a zip into a byte[] is a byte[] of the zip not the assembly, decompress the zip first. You can use something like http://dotnetzip.codeplex.com ), a free 3rd-party library, to create and read zip files from within any .NET application. . .

   string unpackDirectory = "ExtractedFiles";      
   using (ZipFile zip1 = ZipFile.Read(zipToUnpack))      
   {
       // here, we extract every entry, but we could extract conditionally          
       // based on entry name, size, date, checkbox status, etc.            
       foreach (ZipEntry e in zip1)          
       {            
           e.Extract(unpackDirectory, ExtractExistingFileAction.OverwriteSilently);          
       }      
    }