注:我已要求相关的问题(与所接受的答案):How to combine DataTrigger and Trigger?
我想我需要一个EventTrigger
和DataTrigger
达到什么样的我后我结合:
目前,我有一个DataTemplate,看起来像这样:
<DataTemplate DataType="{x:Type Notifications:NotificationViewModel}">
<Grid HorizontalAlignment="Stretch">
<Border Name="Background" CornerRadius="8" Background="#80c0c0c0" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" />
<Border Name="Highlight" CornerRadius="8" Background="Red" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" />
<!-- snip actual visual stuff -->
<Grid.Triggers>
<EventTrigger RoutedEvent="Grid.Loaded">
<EventTrigger.Actions>
<BeginStoryboard>
<Storyboard>
<DoubleAnimation x:Name="LoadedAnimation"
Storyboard.TargetName="Highlight"
Storyboard.TargetProperty="Opacity"
From="0" To="1"
RepeatBehavior="5x"
Duration="0:00:0.2"
AutoReverse="True" />
</Storyboard>
</BeginStoryboard>
</EventTrigger.Actions>
</EventTrigger>
</Grid.Triggers>
</Grid>
<DataTemplate.Triggers>
<DataTrigger Binding="{Binding Path=IsCritical}" Value="True">
<Setter TargetName="LoadedAnimation" Property="RepeatBehavior" Value="5.5x" />
</DataTrigger>
</DataTemplate.Triggers>
</DataTemplate>
这个想法是,一个EventTrigger动画0和1之间来回反复,当第一次加载项,将用户的注意力,以它的Highlight
边界的不透明度。所述DataTrigger
确定的倍动画数。如果视图模型报告该项目IsCritical
那么动画发生5.5倍(例如,它在不透明度1结束),否则它发生5次(不透明度为0。结尾)
然而上述XAML不起作用,因为DataTrigger的setter失败:
儿童与名称“LoadedAnimation”中的VisualTree没有找到。
很公平。因此,害羞使用自定义值转换器,或将动画计数的视图模型,并结合它的,有哪些选择?
我会用一个行为的INSTEAD OF触发器在这种情况下。您可以编写附加一个事件处理程序关联的对象的load事件,然后应用动画行为。该行为可能会暴露一些属性,我会暴露,告诉的行为多少时间来重复它与关联的元素上动画的AnimationCount(INT)属性。然后,您可以将此属性设置为IsCritical属性绑定在视图模型,并使用值转换器转换成假以5和真实5.5
希望这可以帮助
如果你有到混和SDK接入(你应该,如果你正在使用VS2012 +),你应该能够在XAML完全做到这一点,像这样的东西(免责声明:未经测试):
<Grid HorizontalAlignment="Stretch">
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="NotificationStates">
<VisualState x:Name="Flashing">
<Storyboard>
<DoubleAnimation x:Name="LoadedAnimation"
Storyboard.TargetName="Highlight"
Storyboard.TargetProperty="Opacity"
From="0" To="1"
RepeatBehavior="5x"
Duration="0:00:0.2"
AutoReverse="True" />
</Storyboard>
</VisualState>
<VisualState x:Name="Normal" />
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<Border Name="Background" CornerRadius="8" Background="#80c0c0c0" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" />
<Border Name="Highlight" CornerRadius="8" Background="Red" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" />
<!-- snip actual visual stuff -->
<i:Interaction.Triggers>
<i:EventTrigger EventName="Loaded">
<ic:GoToStateAction StateName="Flashing"/>
</i:EventTrigger>
<ie:DataTrigger Binding="{Binding Path=IsCritical}" Value="True">
<ic:GoToStateAction StateName="Flashing"/>
</ie:DataTrigger>
</i:Interaction.Triggers>
</Grid>
提取你的故事板到的VisualState,然后使用表达式库的XAML中切换状态。你需要Microsoft.Expression.Interactions库,又见WPF/Silverlight States - Activate from XAML?
我知道你说你不热衷于转换器的想法,但它看起来像混合解决方案需要安装库。该转换器是没有太多的工作和信号的意图,房价是直接依赖于IsCritical
属性:
public class CriticalAnimationRateConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
// Error handling omitted for brevity.
if ((bool)value)
return new System.Windows.Media.Animation.RepeatBehavior(5.5);
else
return new System.Windows.Media.Animation.RepeatBehavior(5.0);
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
throw new NotImplementedException();
}
}
然后更新您的动画:
<DoubleAnimation Storyboard.TargetName="Highlight"
Storyboard.TargetProperty="Opacity"
From="0"
To="1"
RepeatBehavior="{Binding IsCritical, Converter={StaticResource CriticalAnimationRateConverter}}"
Duration="0:00:0.2"
AutoReverse="True" />
然后DataTrigger
可以被删除。
尝试是这样的:
<Style x:Key="EventTriggerStyleKey">
<Style.Triggers>
<EventTrigger RoutedEvent="some event here">
<!-- your animation here -->
</EventTrigger>
<Style.Triggers>
</Style>
<Style x:Key="myStyleKey">
<Style.Triggers>
<DataTrigger Binding="....." Value="......">
<Setter Property="........." Value="......."/>
<Setter Property="Style" Value="{StaticResource EventTriggerStyleKey}"/>
</DataTrigger>
<Style.Triggers>
</Style>