c# - 通过 TemplateBinding 添加 RoutedEvent

Question

我想在 XAML 字典中的 Border 上使用 RoutedEvent。 RoutedEvent 来自模板所在的类，我该如何实现？

ModernWindow.cs

/// <summary>
/// Gets fired when the logo is clicked.
/// </summary>
public static readonly RoutedEvent LogoClickEvent = EventManager.RegisterRoutedEvent("LogoClickRoutedEventHandler", RoutingStrategy.Bubble, typeof(RoutedEventHandler), typeof(ModernWindow));

/// <summary>
/// The routedeventhandler for LogoClick
/// </summary>
public event RoutedEventHandler LogoClick 
{
    add { AddHandler(LogoClickEvent, value); }
    remove { RemoveHandler(LogoClickEvent, value); }
}

/// <summary>
/// 
/// </summary>
protected virtual void OnLogoClick() 
{
    RaiseEvent(new RoutedEventArgs(LogoClickEvent, this));
}

ModernWindow.xaml

<!-- logo -->
<Border MouseLeftButtonDown="{TemplateBinding LogoClick}" Background="{DynamicResource Accent}" Width="36" Height="36" HorizontalAlignment="Right" VerticalAlignment="Top" Margin="0,0,76,0">
    <Image Source="{TemplateBinding Logo}" Stretch="UniformToFill" />
</Border>

Answer 1

我认为在您的情况下，您可以使用 EventSetter，它就是为此而设计的。对你来说，它看起来像这样:

<Style TargetType="{x:Type SomeControl}">
    <EventSetter Event="Border.MouseLeftButtonDown" Handler="LogoClick" />
    ...

</Style>

注意: EvenSetter 不能通过触发器设置，也不能用于主题资源字典中包含的样式，所以通常它放在当前样式的开头。

有关详细信息，请参阅:

EventSetter Class in MSDN

或者，如果您需要在 ResourceDictionary 中使用它，您可以采用不同的方式。创建 DependencyProperty(也可以附加)。带有附加 DependencyProperty 的示例:

属性定义:

public static readonly DependencyProperty SampleProperty =
                                          DependencyProperty.RegisterAttached("Sample",
                                          typeof(bool),
                                          typeof(SampleClass),
                                          new UIPropertyMetadata(false, OnSample));

private static void OnSample(DependencyObject sender, DependencyPropertyChangedEventArgs e)
{
    if (e.NewValue is bool && ((bool)e.NewValue) == true)
    {
        // do something...
    }
}

如果您尝试设置我们名为 On Sample 的属性的值，您将能够在其中执行您需要的操作(几乎和事件一样)。

根据事件设置属性的值，您可能喜欢:

<EventTrigger SourceName="MyBorder" RoutedEvent="Border.MouseLeftButtonDown">
    <BeginStoryboard>
        <Storyboard>
            <ObjectAnimationUsingKeyFrames Storyboard.TargetName="MyBorder" Storyboard.TargetProperty="(local:SampleClass.Sample)">
                <DiscreteObjectKeyFrame KeyTime="0:0:0">
                    <DiscreteObjectKeyFrame.Value>
                        <sys:Boolean>True</sys:Boolean>
                    </DiscreteObjectKeyFrame.Value>
                </DiscreteObjectKeyFrame>
            </ObjectAnimationUsingKeyFrames>
        </Storyboard>
    </BeginStoryboard>
</EventTrigger>