MEF only loading Exports from local assembly - export

Question

Im trying to make an app that can dynamically load classes that implements an interface "IPlugin", i have:
var catalog = new AssemblyCatalog(typeof(Shell).Assembly);
var externalCatalog = new DirectoryCatalog(#".\Modules");
var container = new CompositionContainer(catalog);
var a = new AggregateCatalog(externalCatalog, catalog);
But when im trying to get the exports:
CompositionContainer __container = new CompositionContainer(a);
//get all the exports and load them into the appropriate list tagged with the importmany
__container.Compose(batch);
var yyyy = __container.GetExports<IModule>();
It doesnt find my "IPlugin" in the external assembly "Rejseplan".
Implementation of "Rejseplan" plugin:(the one that does not get loaded)
namespace Rejseplan
{
[ModuleExport(typeof(IPlugin), InitializationMode = InitializationMode.WhenAvailable)]
class RejseplanModule : IModule, IPlugin
{
private readonly IRegionViewRegistry regionViewRegistry;
[ImportingConstructor]
public RejseplanModule(IRegionViewRegistry registry)
{
this.regionViewRegistry = registry;
}
public void Initialize()
{
regionViewRegistry.RegisterViewWithRegion("MainRegion", typeof(Views.DepartureBoard));
}
string IPlugin.Name
{
get { throw new NotImplementedException(); }
}
string IPlugin.Version
{
get { throw new NotImplementedException(); }
}
string IPlugin.TabHeader
{
get { throw new NotImplementedException(); }
}
}
}
implmentation of "Test" plugin (the one that GETS loaded):
namespace HomeSystem
{
[Export(typeof(IPlugin))]
[ModuleExport(typeof(IModule), InitializationMode = InitializationMode.WhenAvailable)]
public class Test : IModule, IPlugin
{
public void Initialize()
{
}
public string Name
{
get { return "Test"; }
}
public string Version
{
get { return "Tis"; }
}
public string TabHeader
{
get { return "Tabt"; }
}
}
}
Hope you guys can helpCheers! :)

Answer 1

to be honest i dont really know what you wanna achieve :)
but if you want to see your RejseplanModule within your call:
__container.GetExports<IModule>();
you have to add the right Export attribute.
RejseplanModule is not MEF marked with Export of type IModule. can you check your code if its a typo or not? at least it should be the following (see the typeof(IModule))
EDIT:
external dll
[Export(typeof(IModule))]//<-- remove this if its handled by your custom ModulExport Attribute
[ModuleExport(typeof(IModule), InitializationMode = InitializationMode.WhenAvailable)]
class RejseplanModule : IModule, IPlugin
{...}
your main app(code from fhnaseer above)
var directoryPath = "path to dll folder";
var asmCatalog = new AssemblyCatalog(Assembly.GetExecutingAssembly());
var directoryCatalog = new DirectoryCatalog(directoryPath, "*.dll");
var aggregateCatalog = new AggregateCatalog();
aggregateCatalog.Catalogs.Add(asmCatalog);
aggregateCatalog.Catalogs.Add(directoryCatalog);
var container = new CompositionContainer(aggregateCatalog);
var allIModulPlugins = container.GetExports<IModule>();

Answer 2

try to do this.
var directoryPath = "path to dll folder";
var asmCatalog = new AssemblyCatalog(Assembly.GetExecutingAssembly());
var directoryCatalog = new DirectoryCatalog(directoryPath, "*.dll");
var aggregateCatalog = new AggregateCatalog();
aggregateCatalog.Catalogs.Add(asmCatalog);
aggregateCatalog.Catalogs.Add(directoryCatalog);
var container = new CompositionContainer(aggregateCatalog);
container.ComposeParts(this);