我希望有人能够在这里提供帮助,或者建议如何解决我所拥有的问题,或者提出一种实现我所追求的更好的方法。
我有一个简单的自定义控件,希望在该控件上启动/停止/暂停/恢复不透明度动画。我研究了各种解决方案,并认为将EventTrigger
与自定义RoutedEvent
结合使用是前进的道路。我可以将以下内容用于标准事件(例如MouseDown
),但无法获取自定义事件来启动情节提要。
我在加载事件中尝试过在构造函数中引发事件,但两者没有任何区别。
我认为它没有任何相关影响,但是它也存在于Winforms的ElementHost
中。
xaml:
<UserControl x:Class="Fraxinus.BedManagement.WpfControls.FraxIconX"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:local="clr-namespace:Fraxinus.BedManagement.WpfControls"
mc:Ignorable="d"
d:DesignHeight="16" d:DesignWidth="16"
Loaded="FraxIconX_Loaded">
<!--Height="16" Width="16" Background="{Binding Path=Background, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Control}, AncestorLevel=1}}" -->
<UserControl.Resources>
<ResourceDictionary>
<Border x:Key="RoundedBorderMask" Name="iconBorder" CornerRadius="4" Background="White" BorderThickness="2" Height="16" Width="16" HorizontalAlignment="Center" VerticalAlignment="Center"/>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="Dictionary.xaml"/>
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
</UserControl.Resources>
<Border BorderThickness="2" CornerRadius="4" Height="16" Width="16" HorizontalAlignment="Center" VerticalAlignment="Center">
<local:FraxCanvas x:Name="fraxCanvas" Height="16" Width="16" HorizontalAlignment="Center" VerticalAlignment="Center">
<local:FraxCanvas.Background>
<LinearGradientBrush StartPoint="0,0" EndPoint="0,1" GradientStops="{Binding GradientStops}" />
</local:FraxCanvas.Background>
<local:FraxCanvas.Triggers>
<EventTrigger RoutedEvent="local:FraxCanvas.OnStartStoryboard" SourceName="fraxCanvas">
<BeginStoryboard x:Name="storyboard">
<Storyboard>
<DoubleAnimation Storyboard.TargetProperty="Opacity" From="1" To="0.25" AutoReverse="True" Duration="0:0:1" RepeatBehavior="Forever"></DoubleAnimation>
</Storyboard>
</BeginStoryboard>
</EventTrigger>
</local:FraxCanvas.Triggers>
<local:FraxCanvas.OpacityMask>
<!--https://wpf.2000things.com/2012/05/11/556-clipping-to-a-border-using-an-opacity-mask/-->
<VisualBrush Visual="{StaticResource RoundedBorderMask}"></VisualBrush>
</local:FraxCanvas.OpacityMask>
<Image HorizontalAlignment="Center" VerticalAlignment="Center" Height="16" Width="16" Source="{DynamicResource BitmapClockPng}" />
</local:FraxCanvas>
</Border>
</UserControl>
后面的代码
public partial class FraxIconX : UserControl
{
public GradientStopCollection GradientStops { get; set; }
public FraxIconX() { }
public FraxIconX(Color backColour, int width = 16, int height = 16)
{
Width = width;
Height = height;
GradientStops = new GradientStopCollection { new GradientStop(Colors.AliceBlue, 0.0), new GradientStop(Colors.Navy, 1.0) };
Background = new SolidColorBrush(backColour);
DataContext = this;
InitializeComponent();
}
public void FraxIconX_Loaded(object sender, RoutedEventArgs args)
{
RaiseEvent(new RoutedEventArgs(FraxCanvas.StartStoryboardEvent));
}
}
FraxCanvas:
public class FraxCanvas : Canvas
{
public static readonly RoutedEvent StartStoryboardEvent = EventManager.RegisterRoutedEvent("OnStartStoryboard", RoutingStrategy.Tunnel, typeof(RoutedEventHandler), typeof(FraxCanvas));
public event RoutedEventHandler OnStartStoryboard
{
add
{
this.AddHandler(StartStoryboardEvent, value);
}
remove
{
this.RemoveHandler(StartStoryboardEvent, value);
}
}
}
两个问题。
EventTrigger.SourceName="fraxCanvas"
,但是该事件在其他地方(父级UserControl
)引发。EventTrigger.SourceName
是一个过滤器属性,它允许仅侦听特定元素的路由事件。如果您不设置它,触发器将监听指定的事件,无论来源。FraxCanvas
元素,因为父级将其引发。RoutingStrategy.Bubble
:事件从[FraxIconX
元素事件源传播到视觉树的根,例如Window
。RoutingStrategy.Tunnel
:事件从树的根开始传播,例如,在[[事件源,Window
元素处,FraxIconX
和stops。EventTrigger.SourceName
属性,并将触发器移至事件源(UserControl
)或事件源的任何父元素:<UserControl>
<UserControl.Triggers>
<EventTrigger RoutedEvent="local:FraxCanvas.OnStartStoryboard">
<BeginStoryboard x:Name="storyboard">
<Storyboard>
<DoubleAnimation Storyboard.TargetName="fraxCanvas"
Storyboard.TargetProperty="Opacity"
From="1" To="0.25" />
</Storyboard>
</BeginStoryboard>
</EventTrigger>
</UserControl.Triggers>
<Border>
<FraxCanvas x:Name="fraxCanvas" />
</Border>
</UserControl>