C# 如何在导体上对ActivateItem进行单元测试

考虑以下Viewmodel：

 public class MainViewModel : Conductor<object>
{
    private readonly IEventAggregator eventAggregator;
    private readonly IWindowManager windowManager;
    IConfigurationViewModel configurationViewModel;

    /// <summary>
    /// Initializes a new instance of the MainViewModel class.
    /// </summary>
    public MainViewModel(IEventAggregator eventAggregator,IWindowManager windowManager,IConfigurationViewModel configurationViewModel)
    {
        this.eventAggregator = eventAggregator;
        this.windowManager = windowManager;
        this.eventAggregator.Subscribe(this);
        this.configurationViewModel = configurationViewModel;
    }

    public void GoToConfiguration()
    {
        ActivateItem(configurationViewModel);
    }

}

 public interface IConfigurationViewModel:IScreen
{

}
public class ConfigurationViewModel :Screen, IConfigurationViewModel
{

}

---

问题在于，由于

MainViewModel

未激活，因此它将不会激活

ConfigurationViewModel

[Fact]
public void GoToConfigurationActivatesCorrectViewModel()
{
    var configuration = new ConfigurationViewModel();
    var main = new MainViewModel(configuration);

    ScreenExtensions.TryActivate(main);

    main.GoToConfiguration();

    Assert.True(configuration.IsActive);
}

此测试通过了重要的一行，即首先激活视图模型

[Fact]
public void GoToConfigurationActivatesCorrectViewModel()
{
    var configuration = new ConfigurationViewModel();
    var main = new MainViewModel(configuration);

    ScreenExtensions.TryActivate(main);

    main.GoToConfiguration();

    Assert.True(configuration.IsActive);
}