Bootstrapper.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.ComponentModel.Composition;
using System.ComponentModel.Composition.Hosting;
using System.ComponentModel.Composition.Primitives;
using Caliburn.Micro;
using tag.ViewModels.Interfaces;

namespace tag
{
  public class Bootstrapper : Bootstrapper<IShell>
  {
    private CompositionContainer container;

    protected override void Configure()
    {
      container = new CompositionContainer(new AggregateCatalog(AssemblySource.Instance.Select(x => new AssemblyCatalog(x)).OfType<ComposablePartCatalog>()));

      CompositionBatch batch = new CompositionBatch();

      batch.AddExportedValue<IWindowManager>(new WindowManager());
      batch.AddExportedValue<IEventAggregator>(new EventAggregator());
      batch.AddExportedValue(container);

      container.Compose(batch);
    }

    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.Count() > 0)
      {
        return exports.First();
      }

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