Cannot Serialize of list of objects which contain a reflected type.

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Hi,

I'm having a problem serialising a List of Objects.

Each object is a class, whose attributes are derived from a schema table returned by an SQL query.

The data-type of each object is determined using reflection and at the same time a .dll is built.

The eventual plan is that after the data is retrieved, the newly populated List of Objects is serialised to XML and then de-serialised into a separate application. To gain access to the attributes of the newly created POCO a '.dll' is generated.

The problem arises when attempting to serialise this class:

List<Type> noDuplicates = expectedTypes.Distinct().ToList(); // captured when creating the .dll
// start of serialization process
con.Message( "starting serialization" );
XmlSerializer serializer = new XmlSerializer(/* Trouble arises here */ , noDuplicates.ToArray<Type>());
MemoryStream stream = new MemoryStream();
serializer.Serialize(stream, outputList); // Throws exception "Unable to generate XML document

When passing the type into the XmlSerializer I am unsure how to get the type of the reflected POCO that has been created.

Thank you in advance for any feedback or solutions.

Larrythemule

-- Addition --

Hi,

I have tried this since posting last time:

XML

const string TypeName = "myType";
//Code
TypeBuilder tb = mb.DefineType( TypeName, TypeAttributes.Public | TypeAttributes.Serializable );
// Some Code
Type generatedType = tb.CreateType();
ab.Save( aName.Name + ".dll" );
XmlSerializer serializer = new XmlSerializer(generatedType, noDuplicates.ToArray<Type>());

This was an attempt to pass the correct type into the XMLSerialiser. Instead of throwing an exception immediately, there was a pause, suggesting that the document was at least partially serialised. The same exception was thrown however.

Thanks again.

Posted 8-Nov-10 3:55am

Laurence1234

Updated 8-Nov-10 4:29am

v3

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JeremH · Answer 1 · 2010-11-08T04:24:00

Solution 1

Hi,

If you don't must to use a List , you can use an Array

XML

Type[] noDuplicates = expectedTypes.Distinct().ToArray(); 
con.Message( "starting serialization" );
XmlSerializer serializer = new XmlSerializer(/* Trouble arises here */ , noDuplicates.ToArray());
MemoryStream stream = new MemoryStream();
serializer.Serialize(stream, outputList); // Throws exception "Unable to generate XML document

you can try this

good luck

jerem

Posted 8-Nov-10 4:24am

JeremH

Comments

jim lahey 8-Nov-10 10:32am

He already does:

XmlSerializer serializer = new XmlSerializer(/* Trouble arises here */ , noDuplicates.ToArray

Laurence1234 8-Nov-10 10:33am

Hi Jim and Jerem,
Thanks for your feedback Jerem, Jim is right though I'm afraid as I'm already converting my List into an Array of Types.

Type[] myArray [gives the same data structure as] myList.ToArray< Type >()

Laurence1234 · Answer 2 · 2010-11-08T05:09:00

Hi,

Whilst I think that this technically answers the question I have asked here, the overall problem is not solved.

Type ListOfGeneratedObjType = typeof(List<>).MakeGenericType(new Type[] { generatedType });// Creates a List of my new reflected types
//This new list can then be passed to the XmlSerializer and treated as "List<NewType>"
XmlSerializer serializer = new XmlSerializer(ListOfGeneratedObjType, noDuplicates.ToArray<Type>());

There are still issues with the serialisation process but it seems more likely now that is due to the data that is being passed into the list.

The "XmlSerializer" class should be able to properly serialise from a list with those given parameters, as when stepping into the code I can confirm that the "ListOfGeneratedObjType" is correct.