Procedura: aggiungere un valore di output dell'animazione a un valore iniziale dell'animazione
Aggiornamento: novembre 2007
In questo esempio viene illustrato come aggiungere un valore di output dell'animazione a un valore iniziale dell'animazione.
Esempio
La proprietà IsAdditive specifica se si desidera che il valore di output di un'animazione venga aggiunto al valore iniziale (valore di base) di una proprietà animata. È possibile utilizzare la proprietà IsAdditive con la maggior parte delle animazioni di base e con la maggior parte delle animazioni con fotogrammi chiave. Per ulteriori informazioni, vedere Cenni preliminari sull'animazione e Cenni preliminari sulle animazioni con fotogrammi chiave.
Nell'esempio seguente è illustrato l'effetto dell'utilizzo della proprietà DoubleAnimation.IsAdditive con DoubleAnimation e dell'utilizzo della proprietà DoubleAnimationUsingKeyFrames.IsAdditive con DoubleAnimationUsingKeyFrames.
<Page xmlns="https://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="https://schemas.microsoft.com/winfx/2006/xaml">
<StackPanel Margin="20" >
<!-- This rectangle is animated with DoubleAnimation and IsAdditive set to "True". -->
<Rectangle Name="withIsAdditive"
Width="100" Height="20" Margin="12,0,0,5" Fill="#AA3333FF" HorizontalAlignment="Left" />
<!-- This rectangle is animated with DoubleAnimation and IsAdditive set to "False". -->
<Rectangle Name="withoutIsAdditive"
Width="100" Height="20" Margin="12,0,0,5" Fill="#AA3333FF" HorizontalAlignment="Left" />
<!-- This rectangle is animated with DoubleAnimationUsingKeyFrames and IsAdditive set to "True". -->
<Rectangle Name="withIsAdditiveUsingKeyFrames"
Width="100" Height="20" Margin="12,0,0,5" Fill="#AA3333FF" HorizontalAlignment="Left" />
<!-- This rectangle is animated with DoubleAnimationUsingKeyFrames and IsAdditive set to "False". -->
<Rectangle Name="withoutIsAdditiveUsingKeyFrames"
Width="100" Height="20" Margin="12,0,0,5" Fill="#AA3333FF" HorizontalAlignment="Left" />
<!-- Create a button to restart the animations. -->
<Button Margin="0,30,0,0" HorizontalAlignment="Left">
Restart Animations
<Button.Triggers>
<EventTrigger RoutedEvent="Button.Click">
<BeginStoryboard>
<Storyboard>
<!-- DoubleAnimation with IsAdditive set to "True". Because IsAdditive is set to "True" the
actual starting value of the animation is equal to the sum of the default starting
value of 100 (From="100)and the animation output value of 100 (From="100" To="200") Therefore
the animation begins at 200 pixels. Notice that each time the button is clicked and the
animation is initiated, the animation starting value builds upon the preceeding ending value. -->
<DoubleAnimation
Storyboard.TargetName="withIsAdditive"
Storyboard.TargetProperty="Width"
Duration="0:0:3" From="100" To="200" IsAdditive="True" />
<!-- DoubleAnimation with IsAdditive set to "False". The starting value is the default starting
value of 100 pixels and subsequent animations do not build on earlier ones. -->
<DoubleAnimation
Storyboard.TargetName="withoutIsAdditive"
Storyboard.TargetProperty="Width"
Duration="0:0:3" From="100" To="200" IsAdditive="False" />
<!-- DoubleAnimationUsingKeyFrames with IsAdditive set to "True". Similar to the DoubleAnimation
above, this animation adds its output value to its starting value. Note that the output value
is the total output value from all the key frames for a total output of 100 pixels. -->
<DoubleAnimationUsingKeyFrames
Storyboard.TargetName="withIsAdditiveUsingKeyFrames"
Storyboard.TargetProperty="Width"
IsAdditive="True" >
<DoubleAnimationUsingKeyFrames.KeyFrames>
<LinearDoubleKeyFrame Value="100" KeyTime="0:0:0" />
<LinearDoubleKeyFrame Value="130" KeyTime="0:0:1" />
<SplineDoubleKeyFrame KeySpline="0.6,0.0 0.9,0.00" Value="200" KeyTime="0:0:3" />
</DoubleAnimationUsingKeyFrames.KeyFrames>
</DoubleAnimationUsingKeyFrames>
<!-- DoubleAnimationUsingKeyFrames with IsAdditive set to "False". The starting value is the
default starting value of 100 pixels and subsequent animations do not build on earlier ones. -->
<DoubleAnimationUsingKeyFrames
Storyboard.TargetName="withoutIsAdditiveUsingKeyFrames"
Storyboard.TargetProperty="Width"
IsAdditive="False" >
<DoubleAnimationUsingKeyFrames.KeyFrames>
<LinearDoubleKeyFrame Value="100" KeyTime="0:0:0" />
<LinearDoubleKeyFrame Value="130" KeyTime="0:0:1" />
<SplineDoubleKeyFrame KeySpline="0.6,0.0 0.9,0.00" Value="200" KeyTime="0:0:3" />
</DoubleAnimationUsingKeyFrames.KeyFrames>
</DoubleAnimationUsingKeyFrames>
</Storyboard>
</BeginStoryboard>
</EventTrigger>
</Button.Triggers>
</Button>
</StackPanel>
</Page>
Vedere anche
Attività
Procedura: accumulare valori di animazione durante i cicli ripetuti
Concetti
Cenni preliminari sull'animazione
Cenni preliminari sulle animazioni con fotogrammi chiave
Altre risorse
Animazione e sistema di temporizzazione
Procedure relative all'animazione e al sistema di temporizzazione