使用带有 caliburn 微 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：

当我尝试添加一个正常的事件触发器时，一切正常，所以这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？ 有没有办法附加一个附加的事件并使用 caliburn micro 调用它？

Answer 1

我终于明白了问题和解决方案。 问题是 system.windows.interactiviy.EventTrigger 不支持附加事件。 Caliburn micro 将其用于操作，因此我附加的事件不起作用。 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 动作时：

<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>

Answer 2

我不认为缩短 Message.Attach 语法的解析器支持附加事件。但是为什么不直接将 ActionMessage 添加到 EventTrigger 的 Actions 中呢？

<EventTrigger RoutedEvent="Helpers:DataChanging.Changing">
    <EventTrigger.Actions>
        <!-- new part -->
        <cal:ActionMessage MethodName="SelectedDataChanged">  
            <cal:Parameter Value="$eventargs" />  
        </cal:ActionMessage>  
        <!-- /new part -->
        <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>

Answer 3

你试过了吗？

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

我需要从子控件向父 ViewModel 发送一个事件，这对我来说效果很好。我会发布一些示例代码，也许它会帮助别人！

儿童控制代码隐藏：

public partial class MyControl : UserControl
{
    public MyControl()
    {
        InitializeComponent();
    }

    #region Routed Events

    public static readonly RoutedEvent ControlClosedEvent = EventManager.RegisterRoutedEvent(
        "ControlClosed",
        RoutingStrategy.Bubble,
        typeof(RoutedEventHandler),
        typeof(MyControl));

    public event RoutedEventHandler ControlClosed
    {
        add { AddHandler(ControlClosedEvent, value); }
        remove { RemoveHandler(ControlClosedEvent, value); }
    }

    #endregion Routed Events

    private void Close(object sender, RoutedEventArgs e)
    {
        var rea = new RoutedEventArgs(ControlClosedEvent);
        RaiseEvent(rea);
    }
}

子控件 XAML：

<Button Grid.Row="1" Grid.Column="0"
        Content="Close Me!" Height="50"
        Click="Close" />

父视图：

<userControls:MyControl cal:Message.Attach="[Event ControlClosed] = [Action ClosePopup]" />