c# - 使用带有 Caliburn micro Message.Attach 的附加事件

Question

我正在尝试使用 Caliburn 微消息来触发我创建的附加事件:

public static class DataChanging
{

    public delegate void DataChangingEventHandler(object sender, DataChangingEventArgs e);
    public static readonly RoutedEvent ChangingEvent =
        EventManager.RegisterRoutedEvent("Changing",
                                         RoutingStrategy.Bubble,
                                         typeof(DataChangingEventHandler),
                                         typeof(DataChanging));

    public static void AddChangingHandler(DependencyObject o, DataChangingEventHandler handler)
    {
        ((UIElement)o).AddHandler(DataChanging.ChangingEvent, handler);
    }
    public static void RemoveChangingHandler(DependencyObject o, DataChangingEventHandler handler)
    {
        ((UIElement)o).RemoveHandler(DataChanging.ChangingEvent, handler);
    }

    public static bool GetActivationMode(DependencyObject obj)
    {
        return (bool)obj.GetValue(ActivationModeProperty);
    }
    public static void SetActivationMode(DependencyObject obj, bool value)
    {
        obj.SetValue(ActivationModeProperty, value);
    }
    public static readonly DependencyProperty ActivationModeProperty =
        DependencyProperty.RegisterAttached("ActivationMode",
                                            typeof(bool),
                                            typeof(DataChanging),
                                            new FrameworkPropertyMetadata(false,
                                                                          HandleActivationModeChanged));

    private static void HandleActivationModeChanged(DependencyObject target, DependencyPropertyChangedEventArgs e)
    {
        var dataGrid = target as XamDataGrid;
        if (dataGrid == null) // if trying to attach to something else than a datagrid, just ignore
            return;
        if ((bool)e.NewValue)
        {
            dataGrid.RecordDeactivating += selector_RecordDeactivating;
        }
        else
        {
            dataGrid.RecordDeactivating -= selector_RecordDeactivating;
        }
    }

    static void selector_RecordDeactivating(object sender, RecordDeactivatingEventArgs e)
    {

        var args = new DataChangingEventArgs(DataChanging.ChangingEvent,sender)
                       {
                           Data = ((DataRecord) e.Record).DataItem, 
                           ShouldCancelChange = false
                       };
        (sender as UIElement).RaiseEvent(args);
        e.Cancel = args.ShouldCancelChange;
    }
}

在 XAML 本身中，我添加了以下行:

cal:Message.Attach="[Helpers:DataChanging.Changing] = [Action SelectedDataChanged($eventArgs)]"

助手引用正确的命名空间。我还尝试了其他失败的版本(完整命名空间):

cal:Message.Attach="[clr-namespace:RTF.Client.UI.Helpers.DataChanging.Changing] = [Action SelectedDataChanged($eventArgs)]"

尝试自己设置交互事件:

当我尝试添加一个普通事件触发器时，一切正常，所以它不是我附加的事件声明:

 <EventTrigger RoutedEvent="Helpers:DataChanging.Changing">
                    <EventTrigger.Actions>
                        <BeginStoryboard x:Name="sb">
                            <Storyboard x:Name="dsf">
                                <Storyboard x:Name="myStoryboard">
                                    <BooleanAnimationUsingKeyFrames Storyboard.TargetName="SSS" Storyboard.TargetProperty="IsChecked">
                                        <DiscreteBooleanKeyFrame KeyTime="00:00:00" Value="False" />
                                    </BooleanAnimationUsingKeyFrames>
                                </Storyboard>
                            </Storyboard>
                        </BeginStoryboard>
                    </EventTrigger.Actions>
                </EventTrigger>

我在这里做错了什么？无法附加附加事件并使用 Caliburn Micro 调用它？

Answer 1

终于明白问题所在和解决办法了。问题是 system.windows.interactiviy.EventTrigger 不支持附加事件。Caliburn micro 将它用于操作，因此我的附加事件不起作用。解决方案是编写自定义事件触发器并以显式方式使用 Caliburn 微操作。自定义事件触发器取自该帖子:http://joyfulwpf.blogspot.com/2009/05/mvvm-invoking-command-on-attached-event.html?showComment=1323674885597#c8041424175408473805

 public class RoutedEventTrigger : EventTriggerBase<DependencyObject>
{
    RoutedEvent _routedEvent; 
    public RoutedEvent RoutedEvent
    {
        get { return _routedEvent; } 
        set { _routedEvent = value; }
    } 

    public RoutedEventTrigger() { } 
    protected override void OnAttached()
    {
        Behavior behavior = base.AssociatedObject as Behavior; 
        FrameworkElement associatedElement = base.AssociatedObject as FrameworkElement; 
        if (behavior != null)
        {
            associatedElement = ((IAttachedObject)behavior).AssociatedObject as FrameworkElement;
        } 
        if (associatedElement == null)
        {
            throw new ArgumentException("Routed Event trigger can only be associated to framework elements");
        } 
        if (RoutedEvent != null) 
        { associatedElement.AddHandler(RoutedEvent, new RoutedEventHandler(this.OnRoutedEvent)); }
    } 
    void OnRoutedEvent(object sender, RoutedEventArgs args)
    {
        base.OnEvent(args);
    } 
    protected override string GetEventName() { return RoutedEvent.Name; }
}

然后当你想使用 caliburn Action 时:

<i:Interaction.Triggers>
                <!--in the routed event property you need to put the full name space and event name-->
                <Helpers:RoutedEventTrigger RoutedEvent="Helpers:DataChanging.Changing">
                    <cal:ActionMessage MethodName="SelectedDataChanged">
                        <cal:Parameter Value="$eventargs" />
                    </cal:ActionMessage>
                </Helpers:RoutedEventTrigger>
 </i:Interaction.Triggers>