我有一个Storyboard
动画,如下所示:
<Grid Name="Choice" VerticalAlignment="Stretch" Width="400">
<Interactivity:Interaction.Behaviors>
<Core:EventTriggerBehavior EventName="Tapped">
<Media:ControlStoryboardAction>
<Media:ControlStoryboardAction.Storyboard>
<Storyboard x:Name="Animation">
<DoubleAnimationUsingKeyFrames EnableDependentAnimation="True" Storyboard.TargetProperty="(FrameworkElement.Width)" Storyboard.TargetName="Choice">
<EasingDoubleKeyFrame KeyTime="0" Value="{Binding Path=InitialWidth}"/>
<EasingDoubleKeyFrame KeyTime="0:0:1" Value="{Binding Path=FinalWidth}" />
</DoubleAnimationUsingKeyFrames>
</Storyboard>
</Media:ControlStoryboardAction.Storyboard>
</Media:ControlStoryboardAction>
</Core:EventTriggerBehavior>
</Interactivity:Interaction.Behaviors>
<Image HorizontalAlignment="Center" VerticalAlignment="Center" Source="{Binding Path=Image}" Stretch="UniformToFill" />
</Grid>
我在属性InitialWidth
和FinalWidth
中设置的初始值似乎是正确的,但如果我稍后更改,则它们不会更新,而是0
。我在某处读到,在运行时无法将属性绑定到Storyboard
值,但我没有找到任何正式文档说明。
我的问题是,我可以将属性绑定到Storyboard
值吗?如果是这样,我需要改变什么?
答案 0 :(得分:1)
我无法对此进行测试,因此请将其作为“可能有效”的建议。我们的想法是在您的页面资源中创建一个“代理”对象,然后使用StaticResource
绑定来引用它。
代理只是一个DependencyObject,它包含您对绑定感兴趣的属性:
public class ProxyObject : DependencyObject
{
public double InitialWidth
{
get { return (double)GetValue(InitialWidthProperty); }
set { SetValue(InitialWidthProperty, value); }
}
public static readonly DependencyProperty InitialWidthProperty =
DependencyProperty.Register("InitialWidth", typeof(double), typeof(ProxyObject), new PropertyMetadata(0));
public double FinalWidth
{
get { return (double)GetValue(FinalWidthProperty); }
set { SetValue(FinalWidthProperty, value); }
}
public static readonly DependencyProperty FinalWidthProperty =
DependencyProperty.Register("FinalWidth", typeof(double), typeof(ProxyObject), new PropertyMetadata(0));
}
现在在页面资源中实例化它,并绑定到您的视图模型:
<Grid Name="Choice">
<Grid.Resources>
<ResourceDictionary>
<local:ProxyObject x:Name="proxy"
InitialWidth="{Binding InitialWidth}" FinalWidth="{Binding FinalWidth}" />
</ResourceDictionary>
</Grid.Resources>
...
</Grid>
然后,您可以将其作为时间轴元素中的静态资源引用:
<EasingDoubleKeyFrame KeyTime="0"
Value="{Binding Source="{StaticResource proxy},Path=InitialWidth}" />
<EasingDoubleKeyFrame KeyTime="0:0:1"
Value="{Binding Source="{StaticResource proxy},Path=InitialWidth}" />
我已成功使用Silverlight中的类似内容(控件模板中的可视状态故事板),但我不确定它是否适用于您的场景。