wpf 基于可见性停止/开始故事板动画
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Stop / start storyboard animation based on Visibility
提问by Chris
I have an animation that currently starts when a Controlis loaded (the animation is essentially a waiting spinner, that is applied to an empty ContentControl).
我有一个当前在Control加载a 时开始的动画（动画本质上是一个等待的微调器，应用于空的ContentControl）。
The animation however will constantly spin taking up resources. What I'd like is for the animation to start / stop based on whether the animation control is visible or not, is this possible?
然而，动画会不断旋转占用资源。我想要的是根据动画控件是否可见来开始/停止动画，这可能吗？
<Canvas.Triggers>
<EventTrigger RoutedEvent="ContentControl.Loaded">
<BeginStoryboard>
<Storyboard>
<DoubleAnimation
Storyboard.TargetName="SpinnerRotate"
Storyboard.TargetProperty="Angle"
From="0" To="360" Duration="0:0:01.3"
RepeatBehavior="Forever" />
</Storyboard>
</BeginStoryboard>
</EventTrigger>
</Canvas.Triggers>
I must have this working for both Silverlight and WPF.
我必须同时为 Silverlight 和 WPF 工作。
回答by New Dev
Might not be elegant, but works.
可能不优雅，但有效。
<Border x:Name="square" Height="20" Width="20" Background="Aqua">
<Border.Triggers>
<EventTrigger RoutedEvent="Loaded">
<BeginStoryboard>
<Storyboard x:Name="spinner">
<DoubleAnimation
Storyboard.TargetName="square"
Storyboard.TargetProperty="Opacity"
From="1" To="0" Duration="0:0:01.3"
AutoReverse="True"
RepeatBehavior="Forever" />
</Storyboard>
</BeginStoryboard>
</EventTrigger>
</Border.Triggers>
<Border.Style>
<Style>
<Style.Triggers>
<DataTrigger Binding="{Binding Source={RelativeSource Self}, Path=Visibility}" Value="{x:Static Visibility.Collapsed}">
<DataTrigger.EnterActions>
<StopStoryboard BeginStoryboardName="spinner"/>
</DataTrigger.EnterActions>
</DataTrigger>
</Style.Triggers>
</Style>
</Border.Style>
</Border>
回答by Richard E
I have created an example of spinning an Ellipsebased on the Visibilityproperty. Perhaps you can use something from this.
我创建了一个Ellipse基于Visibility属性旋转的示例。也许你可以从这里使用一些东西。
<Canvas>
<Ellipse x:Name="Circle" Width="30" Height="30"
Canvas.Left="50"
Canvas.Top="50">
<Ellipse.Fill>
<LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
<GradientStop Color="Black" Offset="0"/>
<GradientStop Color="White" Offset="1"/>
</LinearGradientBrush>
</Ellipse.Fill>
<Ellipse.RenderTransform>
<RotateTransform x:Name="SpinnerRotate" CenterX="15" CenterY="15"/>
</Ellipse.RenderTransform>
<Ellipse.Style>
<Style TargetType="Ellipse">
<Style.Triggers>
<Trigger Property="Visibility" Value="Visible">
<Trigger.EnterActions>
<BeginStoryboard x:Name="SpinStoryboard">
<Storyboard >
<DoubleAnimation Storyboard.TargetProperty="RenderTransform.Angle"
From="0" To="360" Duration="0:0:01.3"
RepeatBehavior="Forever" />
</Storyboard>
</BeginStoryboard>
</Trigger.EnterActions>
<Trigger.ExitActions>
<StopStoryboard BeginStoryboardName="SpinStoryboard"></StopStoryboard>
</Trigger.ExitActions>
</Trigger>
</Style.Triggers>
</Style>
</Ellipse.Style>
</Ellipse>
</Canvas>
