Question

我有一个带有搜索字段的屏幕视图模型和一些结果，由多个较小的视图模型组成：搜索字段的控件和每个结果的控件实例。

我的＆＃34;容器＆＃34; viewmodel（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);
    }
}

＆＃34;快速搜索＆＃34; （使用搜索字段）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));
    }
}

视图按预期显示，搜索按钮触发SearchReference方法。

但事件似乎没有冒出ShippingViewModel，Handle永远不会被触发。

谢谢！

Answer 1

您似乎永远不会订阅ShippingViewModel中的活动。尝试修改你的构造函数：

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

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

使用Caliburn.Micro在视图模型中冒泡

1 个答案: