使用Caliburn.Micro的视图模型中的气泡事件

Question

我有一个带有搜索字段和一些结果的屏幕视图模型，该视图模型由多个较小的视图模型组成：用于搜索字段的控件，以及每个结果的控件实例。

我的“容器”视图模型（带有搜索和结果）如下所示：

[Export(typeof(ShippingViewModel))]
public class ShippingViewModel : Screen, IHandle<SearchReferenceEvent>
{
    private readonly IEventAggregator events;

    [ImportingConstructor]
    public ShippingViewModel(IEventAggregator events)
    {
        this.events = events;

        this.Search = new QuickSearchViewModel(this.events);
    }

    public QuickSearchViewModel Search { get; set; }

    public void Handle(SearchReferenceEvent message)
    {
        System.Windows.MessageBox.Show(message.Reference);
    }
}

和“快速搜索”（带有搜索字段）viewmodel：

[Export(typeof(QuickSearchViewModel))]
public class QuickSearchViewModel : PropertyChangedBase
{
    private readonly IEventAggregator events;

    private string currentSearch;

    [ImportingConstructor]
    public QuickSearchViewModel(IEventAggregator events)
    {
        this.events = events;
    }

    public string CurrentSearch // bound to the search field
    {
        get
        {
            return this.currentSearch;
        }

        set
        {
            this.currentSearch = value;
            this.NotifyOfPropertyChange(() => this.CurrentSearch);
        }
    }

    public void SearchReference(string reference) // bound to the search button
    {
        this.events.Publish(new SearchReferenceEvent(reference));
    }
}

该视图将按预期显示，并且搜索按钮触发SearchReference方法。

但是该事件似乎没有冒泡到ShippingViewModel ，从未触发过Handle 。

谢谢！

Answer 1

看来您从未订阅ShippingViewModel的事件。 尝试像这样修改构造函数：

[ImportingConstructor]
public ShippingViewModel(IEventAggregator events)
{
    this.events = events;
    this.events.Subscribe(this); // <= register to receive events

    this.Search = new QuickSearchViewModel(this.events);
}