问MEF2 & Caliburn.Micro - IWindowManager和IEventAggregator不导入ShellViewModel

EN

using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows;
using Caliburn.Micro;
using System.ComponentModel.Composition;
using System.ComponentModel.Composition.Hosting;
using System.ComponentModel.Composition.Registration;
using System.Reflection;
using MEF2Test.ViewModels;

namespace MEF2Test
{
    public class MefBootstrapper : BootstrapperBase
    {
        private CompositionContainer _container;

        public MefBootstrapper()
        {
            Initialize();
        }

        protected override void Configure()
        {
            RegistrationBuilder cmBuilder = new RegistrationBuilder();
            RegistrationBuilder cmpBuilder = new RegistrationBuilder();
            RegistrationBuilder vmBuilder = new RegistrationBuilder();

            cmBuilder.ForTypesDerivedFrom<IEventAggregator>().Export<IEventAggregator>();
            cmpBuilder.ForTypesDerivedFrom<IWindowManager>().Export<IWindowManager>();
            vmBuilder.ForTypesDerivedFrom<IShell>().Export<IShell>();

            // These added based on a reference I read, to use ImportProperty
            vmBuilder.ForTypesDerivedFrom<IShell>().ImportProperty<IEventAggregator>(x => x.EventAggregator);
            vmBuilder.ForTypesDerivedFrom<IShell>().ImportProperty<IWindowManager>(x => x.WindowManager);

            AggregateCatalog catalog = new AggregateCatalog();
            AssemblyCatalog cmAssembly = new AssemblyCatalog(typeof(IEventAggregator).GetTypeInfo().Assembly, cmBuilder);
            AssemblyCatalog cmpAssembly = new AssemblyCatalog(typeof(IWindowManager).GetTypeInfo().Assembly, cmpBuilder);
            AssemblyCatalog vmAssembly = new AssemblyCatalog(typeof(MefBootstrapper).GetTypeInfo().Assembly, vmBuilder);

            catalog.Catalogs.Add(cmAssembly);
            catalog.Catalogs.Add(cmpAssembly);
            catalog.Catalogs.Add(vmAssembly);

            _container = new CompositionContainer(catalog, CompositionOptions.DisableSilentRejection | CompositionOptions.IsThreadSafe);
        }

        protected override IEnumerable<Assembly> SelectAssemblies()
        {
            return new[] {
                typeof(IWindowManager).GetTypeInfo().Assembly,
                typeof(IEventAggregator).GetTypeInfo().Assembly,
                typeof(MefBootstrapper).GetTypeInfo().Assembly
            };
        }

        protected override object GetInstance(Type serviceType, string key)
        {
            string contract = string.IsNullOrEmpty(key) ? AttributedModelServices.GetContractName(serviceType) : key;
            var exports = _container.GetExportedValues<object>(contract);

            if (exports.Any())
                return exports.First();

            throw new Exception(string.Format("Could not locate any instances of contract {0}", contract));
        }

        protected override IEnumerable<object> GetAllInstances(Type serviceType)
        {
            return _container.GetExports<object>(AttributedModelServices.GetContractName(serviceType));
        }

        protected override void BuildUp(object instance)
        {
            _container.SatisfyImportsOnce(instance);
        }

        protected override void OnStartup(object sender, StartupEventArgs e)
        {
            DisplayRootViewFor<IShell>();
        }
    }
}

using Caliburn.Micro;

namespace MEF2Test.ViewModels
{
    public class ShellViewModel : Screen, IShell
    {
        private IWindowManager _windowManager;
        private IEventAggregator _eventAggregator;

        public ShellViewModel()
        {
        }

        protected override void OnActivate()
        {
            base.OnActivate();
            _eventAggregator.Subscribe(this);
        }

        protected override void OnDeactivate(bool close)
        {
            base.OnDeactivate(close);
            _eventAggregator.Unsubscribe(this);
        }

        // These 2 Properties added based on a reference I read, to use ImportProperty
        public IEventAggregator EventAggregator
        {
            get { return _eventAggregator; }
            set { _eventAggregator = value; }
        }

        public IWindowManager WindowManager
        {
            get { return _windowManager; }
            set { _windowManager = value; }
        }

    }

    public interface IShell
    {
        // These added based on a reference I read, to use ImportProperty
        IEventAggregator EventAggregator { get; set; }
        IWindowManager WindowManager { get; set; }
    }
}