c# - Caliburn.Micro DisplayRootViewFor 抛出 NullReferenceException

Question

我的 Bootstrap 中有以下代码:

private SimpleContainer container;

protected override void Configure()
{
  container = new SimpleContainer();
  container.Singleton<IEventAggregator, EventAggregator>();
  container.PerRequest<InitialViewModel>();  
}

protected override object GetInstance(Type service, string key)
{
  return container.GetInstance(service, key);
}

protected override IEnumerable<object> GetAllInstances(Type service)
{
  return container.GetAllInstances(service);
}

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

在 OnStartup 方法中，我调用了 DisplayRooViewFor 方法:

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

这是 InitialViewModel:

    private IEventAggregator eventAggregator;    

    public InitialViewModel(IEventAggregator ea) 
    {
      eventAggregator = ea;
    }

不幸的是，它抛出一个NullReferenceException:

An exception of type 'System.NullReferenceException' occurred in Caliburn.Micro.Platform.dll but was not handled in user code

我查看了CM的源代码并使用相同的代码对其进行了测试:

  protected override void OnStartup(object sender, StartupEventArgs e)
    {
      var viewModel = IoC.GetInstance(typeof(InitialViewModel), null);
      var view = ViewLocator.LocateForModel(viewModel, null, null);
      ViewModelBinder.Bind(viewModel, view, null);

      var activator = viewModel as IActivate;
      if (activator != null)
        activator.Activate();

      DisplayRootViewFor<InitialViewModel>();
    }

奇怪的是，这些行没有异常。 view 和 viewmodel 都有引用，InitialView 的构造函数被调用，但是当它到达并调用 DisplayRootViewFor , 它仍然会抛出异常。

我应该改变什么？

Answer 1

我的容器缺少一个关键组件:

container.Singleton<IWindowManager, WindowManager>();