Wpf Caliburn.Micro视图未加载

Question

我是Wpf和Caliburn的新手，我有以下情况，我希望得到一些帮助，我确信代码是正确的，但这不能按预期工作，详细说明

我的AppBootstrapper因此：

public class AppBootstrapper : BootstrapperBase
{
    private CompositionContainer _container;

    public AppBootstrapper()
    {
        this.Initialize();
    }

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

    protected override void Configure()
    {
        try
        {
            this._container = new CompositionContainer(new AggregateCatalog(new DirectoryCatalog(".", "*")));

            var batch = new CompositionBatch();

            batch.AddExportedValue<IWindowManager>(new WindowManager());
            batch.AddExportedValue<IEventAggregator>(new EventAggregator());
            batch.AddExportedValue(this._container);
            this._container.Compose(batch);
        }
        catch (Exception ex)
        {
            this._log.Error(ex.ToString());
        }
    }

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

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

            throw new Exception(string.Format("Could not locate any instances of contract {0}.", contract));
        }
        catch (Exception ex)
        {
            if (ex is ReflectionTypeLoadException)
            {
                var typeLoadException = ex as ReflectionTypeLoadException;
                var loaderExceptions = typeLoadException.LoaderExceptions;
                if (loaderExceptions != null)
                {
                    this._log.Error(loaderExceptions.First().ToString());
                }
            }

            throw;
        }
    }

    protected override IEnumerable<object> GetAllInstances(Type service)
    {
        return this._container.GetExportedValues<object>(AttributedModelServices.GetContractName(service));
    }

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

我的ShellViewModel如下（我删除了一些代码以保持简短）

[Export(typeof(ShellViewModel))]
public class ShellViewModel : Conductor<IScreen>, 
                              IHandle<NavigationEvent>, 
                              IHandle<WindowCloseEnabledEvent>, 
                              IShell, 
                              IShellViewModel
{
    private readonly IEventAggregator _eventAggregator;

    [ImportingConstructor]
    public ShellViewModel(IEventAggregator eventAggregator)
    {
        this._eventAggregator = eventAggregator;
    }

    [Import(typeof(LoginViewModel))]
    public Lazy<IScreen> LoginViewModel { get; set; }

    public void Loaded()
    {
        this._eventAggregator.Subscribe(this);
        this.ActivateItem(this.LoginViewModel.Value);
    }
}

我在ShellView.xaml中有一个触发上面的Loaded方法的事件触发器。

我还有一个LoginViewModel和LoginView（注意这些是在项目的ViewModels和Views文件夹中。

LoginViewModel的重要部分是

[Export(typeof(LoginViewModel))]
public class LoginViewModel : Screen, IAnimatableViewModel, ILoginViewModel
{
    protected override void OnViewLoaded(object view)
    {
        this._view = view;
        IoC.Get<ShellViewModel>().DisableClose = true;
        base.OnViewLoaded(view);
    }
}

此时LoginView.xaml只显示一些文字。

我使用MEF作为DI容器，问题是当我运行应用程序时加载了ShellView，它应该将LoginView加载到其中但是LoginView不加载（或不显示）

如果有人能提供帮助，我们将不胜感激。