Silverlight的双击触发器

Question

相关： "Cleanest single click + double click handling in Silverlight?"

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在XAML中双击触发某些操作的最简单方法是什么？

我正在尝试这样做，当用户双击ListBox项时关闭弹出窗口：

<Popup x:Name="popup">
    <ListBox ItemsSource="{Binding Colors}">
        <ItemsControl.ItemTemplate>
            <DataTemplate>
                <Rectangle Color="{Binding Color}">
                    <i:Interaction.Triggers>
                        <i:EventTrigger EventName="DoubleClick">
                            <ei:ChangePropertyAction TargetObject="{Binding ElementName=popup}"
                                                     PropertyName="IsOpen" Value="False" />
                        </i:EventTrigger>
                    </i:Interaction.Triggers>
                </Rectangle>
            </DataTemplate>
        </ItemsControl.ItemTemplate>
    </ListBox>
</Popup>

上述问题是，当然，没有“DoubleClick”事件。所以我需要用双击触发器替换EventTrigger。

Answer 1

通过继承TriggerBase<T>并将侦听器附加到“MouseLeftButtonDown”事件来创建自定义双击触发器。检查“MouseButtonEventArgs.ClickCount”属性以检查双击：

public class DoubleClickTrigger : TriggerBase<FrameworkElement>
{
    protected override void OnAttached()
    {
        base.OnAttached();
        AssociatedObject.AddHandler(FrameworkElement.MouseLeftButtonDownEvent, new MouseButtonEventHandler(OnClick), true);
    }

    protected override void OnDetaching()
    {
        base.OnDetaching();
        AssociatedObject.RemoveHandler(FrameworkElement.MouseLeftButtonDownEvent, new MouseButtonEventHandler(OnClick));
    }

    private void OnClick(object sender, MouseButtonEventArgs args)
    {
        if (args.ClickCount == 1)
            return;
        if (args.ClickCount == 2)
            InvokeActions(null);
    }
}

这样，OP中的XAML应该通过用上面的DoubleClickTrigger替换EventTrigger来工作。