使用XAML标记的F＃事件处理程序

Question

现在我有Custom Routed Event，如何在XAML中指定处理程序？

<Window.Resources>
    <Style TargetType="Grid">
        <Setter Property="funk:Tap.Handler"
                Value="{Binding TapHandler}"/>
    </Style>
</Window.Resources>

允许：

• 处理冒泡或隧道RoutedEvents的UIElements，而不仅仅是提升它们的控件
• 使用隐式样式，无需为某个类型的每个UIElement连接事件
• 根据ViewModel中的逻辑更改处理程序
• 没有代码隐藏的视图

Answer 1

使用附加属性（基于this post）

type Tap() =
    inherit DependencyObject()

    // For easy exchange
    static let routedEvent = MyButtonSimple.TapEvent

    static let HandlerProperty =
        DependencyProperty.RegisterAttached
            ( "Handler", typeof<RoutedEventHandler>, 
                typeof<Tap>, new PropertyMetadata(null))

    static let OnEvent (sender : obj) args = 
        let control = sender :?> UIElement
        let handler = control.GetValue(HandlerProperty) :?> RoutedEventHandler
        if not <| ((handler, null) ||> LanguagePrimitives.PhysicalEquality) then
            handler.Invoke(sender, args)

    static do EventManager.RegisterClassHandler(
                typeof<FrameworkElement>, routedEvent, 
                    RoutedEventHandler(OnEvent))

    static member GetHandler (element: UIElement) : RoutedEventHandler = 
        element.GetValue(HandlerProperty) :?> _

    static member SetHandler (element: UIElement, value : RoutedEventHandler) = 
        element.SetValue(HandlerProperty, value)

可以找到wpfApp演示文件here（FsXaml 2.1.0）