此示例演示如何使用子 ParallelTimeline 对象简化动画。 Storyboard 是一种 Timeline,可以为其包含的时间线提供目标信息。 使用 a Storyboard 提供时间线目标信息,包括对象和属性信息。
若要开始动画,请使用一个或多个 ParallelTimeline 对象作为嵌套的 Storyboard子元素。 这些 ParallelTimeline 对象可以包含其他动画,因此可以更好地封装复杂动画中的计时序列。 例如,如果要在同一个Storyboard中对一个TextBlock和多个形状进行动画处理,则可以分别分隔TextBlock和形状的动画,并将每个动画放入单独的ParallelTimeline中。 由于每个ParallelTimeline都有其各自的BeginTime,并且ParallelTimeline的所有子元素都是相对于BeginTime开始的,因此计时更好地封装了。
下面的示例对相同Storyboard中的两个文本对象(TextBlock对象)进行动画处理。 封装 ParallelTimeline 其中一个 TextBlock 对象的动画。
性能说明: 虽然可以嵌套 Storyboard 时间线至其他时间线中,但 ParallelTimeline 更适合用于嵌套,因为它们需求较少的开销。 (类 Storyboard 继承自 ParallelTimeline 该类。
示例:
<Page xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<Canvas >
<!-- TextBlock with text "ParallelTimelines are..." that gets animated. -->
<TextBlock Name="FirstTextBlock" Canvas.Top="30" Canvas.Left="300" FontSize="24" >
ParallelTimelines are...
<TextBlock.RenderTransform>
<TransformGroup>
<SkewTransform x:Name="FirstTextBlockSkew" CenterX="25" CenterY="25" AngleX="0" AngleY="0" />
</TransformGroup>
</TextBlock.RenderTransform>
</TextBlock>
<!-- TextBlock with text "Useful" that gets animated. -->
<TextBlock Name="SecondTextBlock" Opacity="0" Canvas.Top="30" Canvas.Left="585" FontSize="24" >
Useful
<TextBlock.RenderTransform>
<TransformGroup>
<SkewTransform x:Name="SecondTextBlockSkew" CenterX="25" CenterY="25" AngleX="0" AngleY="0" />
<ScaleTransform x:Name="SecondTextBlockScale" CenterX="0" CenterY="24" />
</TransformGroup>
</TextBlock.RenderTransform>
</TextBlock>
<!-- Event Trigger that controls all animations on the page. -->
<Canvas.Triggers>
<EventTrigger RoutedEvent="Canvas.Loaded">
<BeginStoryboard>
<Storyboard>
<!-- "ParallelTimelines are..." fades into view. -->
<DoubleAnimation Storyboard.TargetName="FirstTextBlock"
Storyboard.TargetProperty="Opacity" Duration="0:0:2" From="0" To="1" />
<!-- "ParallelTimelines are..." skews to the left. -->
<DoubleAnimation Storyboard.TargetName="FirstTextBlockSkew"
Storyboard.TargetProperty="AngleX" Duration="0:0:1" BeginTime="0:0:2" From="0" To="45" />
<!-- This ParallelTimeline contains all the animations for the TextBlock with the text
"Useful" in it. This ParallelTimeline begins 4 seconds after the Storyboard timeline begins and all child
animations begin relative to this parent timeline. -->
<ParallelTimeline BeginTime="0:0:4">
<!-- "Useful" fades into view. -->
<DoubleAnimation Storyboard.TargetName="SecondTextBlock"
Storyboard.TargetProperty="Opacity" Duration="0:0:2" From="0" To="1" />
<!-- "Useful" slides in from the right. -->
<DoubleAnimation Storyboard.TargetName="SecondTextBlockSkew"
Storyboard.TargetProperty="AngleX" Duration="0:0:2" From="90" To="180" />
<!-- "Useful" skews to the right. -->
<DoubleAnimation Storyboard.TargetName="SecondTextBlockSkew"
Storyboard.TargetProperty="AngleX" BeginTime="0:0:3" Duration="0:0:0.2" From="0" To="-60" />
<!-- "Useful" Gets taller. -->
<DoubleAnimation Storyboard.TargetName="SecondTextBlockScale"
Storyboard.TargetProperty="ScaleY" BeginTime="0:0:3" Duration="0:0:0.2" From="1" To="3" />
</ParallelTimeline>
</Storyboard>
</BeginStoryboard>
</EventTrigger>
</Canvas.Triggers>
</Canvas>
</Page>