MEF - No exports were found that match the constraint

Question

So I have this one class from which I'm trying to import some constructors:

[Export]
public partial class MainWindow
{
        private readonly MainWindowViewModel _viewModel;
        private readonly IEnumerable<IApplicationClosingListener> _applicationClosingListeners;
        private readonly Lazy<IPreferencesRepository> _preferencesRepository;

        [ImportingConstructor]
        public MainWindow(MainWindowViewModel viewModel, IViewManager viewManager, [ImportMany] IEnumerable<IApplicationClosingListener> applicationClosingListeners, Lazy<IPreferencesRepository> preferencesRepository)
        {
            _doStuff();
        }
}

I'm also exporting all the classes that I'm trying to import (MainWindowViewModel, IViewManager and IPreferencesRepository). I do this this way:

MainWindowViewModel and IViewManager classes:

    [Export]
    [Export(typeof(IViewManager))]
    [Export(typeof(IMessagePresenter))]
    public class MainWindowViewModel : BaseViewModel, IViewManager, IApplicationClosingListener
    {
        [ImportingConstructor]
        public MainWindowViewModel(
            Lazy<IPreferencesRepository> preferencesRepository)
        {
            _doStuff();
        }

And finally, IPreferencesRepository class:

[Export(typeof(IPreferencesRepository))]
    public class PreferencesRepository : IPreferencesRepository
    {
        private readonly IPreferencesStorage _preferencesStorage;

        [ImportingConstructor]
        public PreferencesRepository(IPreferencesStorage preferencesStorage, IPreferencesSerializer preferencesSerializer)
        {
            _doStuff();
        }

Now the problem occurs when I'm trying to get and use the exported MainWindow class:

var container = new CompositionContainer(new ApplicationCatalog());
container.ComposeExportedValue((IApplication)this);
var mainWindow = container.GetExport<MainWindow>(); // here the exception is thrown.

The ImportCardinalityMismatchException is thrown. Also, in the debug console I get three messages that are telling me that "No exports were found that match the constraint".

What am I missing?

Answer 1

Probably you don't have export of IPreferencesSerializer.
Also I think your MainWindowViewModel should export IApplicationClosingListener