Timeline.DesiredFrameRate Propriedade Anexada

Definição

Espaço de Nomes:
System.Windows.Media.Animation
Assemblagem:
PresentationCore.dll

Obtém ou define a taxa de frames desejada para esta linha temporal e as suas linhas temporais filhas.

see GetDesiredFrameRate, and SetDesiredFrameRate
see GetDesiredFrameRate, and SetDesiredFrameRate
see GetDesiredFrameRate, and SetDesiredFrameRate

Exemplos

O exemplo seguinte utiliza a propriedade DesiredFrameRate para limitar várias animações a 10 fotogramas por segundo.

<!-- DesiredFrameRateExample.xaml
     This example shows how to use the DesiredFrameRate property. 
     Two DrawingBrushes are animated. The desired frame rate is
     set on one group of animations but not the other, for comparison. -->
<Page xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
  WindowTitle="DesiredFrameRate Example" Background="White">
  <Page.Resources>
  
    <!-- The Drawing used by the animated DrawingBrush. -->
    <DrawingGroup x:Key="CheckerDrawing">
      <GeometryDrawing Brush="White">
        <GeometryDrawing.Geometry>
          <RectangleGeometry Rect="0,0,100,100" />
        </GeometryDrawing.Geometry>
      </GeometryDrawing>
      <GeometryDrawing Brush="Gray">
        <GeometryDrawing.Geometry>
          <RectangleGeometry Rect="0,0,50,50" />
        </GeometryDrawing.Geometry>
      </GeometryDrawing>
      <GeometryDrawing Brush="Gray">
        <GeometryDrawing.Geometry>
          <RectangleGeometry Rect="50,50,50,50" />
        </GeometryDrawing.Geometry>
      </GeometryDrawing>        
    </DrawingGroup>
  </Page.Resources>

  <StackPanel Margin="10">  
    <Rectangle 
      Width="200" Height="200" Margin="10"
      Stroke="Black" StrokeThickness="1" >
      <Rectangle.Fill>
        <DrawingBrush 
          Drawing="{StaticResource CheckerDrawing}"
          Viewport="0,0,50,50" 
          ViewportUnits="Absolute"
          TileMode="Tile"> 
          <DrawingBrush.RelativeTransform>
            <TransformGroup>
              <RotateTransform 
                x:Name="AnimatedRotateTransform1"
                CenterX="0.5" CenterY="0.5" />
              <ScaleTransform
                x:Name="AnimatedScaleTransform1"
                CenterX="0.5" CenterY="0.5" />
            </TransformGroup>
          </DrawingBrush.RelativeTransform>
        </DrawingBrush> 
      </Rectangle.Fill>
      <Rectangle.Triggers>
        <EventTrigger RoutedEvent="Rectangle.Loaded">
          <BeginStoryboard>
          
            <!-- Set the desired framerate on the root timeline. 
                 The animations that belong to this storyboard
                 will be limited to 10 frames per second. -->
            <Storyboard Timeline.DesiredFrameRate="10">
              <DoubleAnimation 
                Storyboard.TargetName="AnimatedRotateTransform1"
                Storyboard.TargetProperty="Angle"
                From="0" To="360" 
                Duration="0:1:00" 
                AutoReverse="True"
                RepeatBehavior="Forever"
                />
              <DoubleAnimation 
                Storyboard.TargetName="AnimatedScaleTransform1"
                Storyboard.TargetProperty="ScaleX"
                From="1" To="5" 
                Duration="0:0:30" 
                AutoReverse="True"
                RepeatBehavior="Forever"
                />
              <DoubleAnimation 
                Storyboard.TargetName="AnimatedScaleTransform1"
                Storyboard.TargetProperty="ScaleY"
                From="1" To="5" 
                Duration="0:0:45" 
                AutoReverse="True"
                RepeatBehavior="Forever"
                />               
            </Storyboard>
          </BeginStoryboard>
        </EventTrigger>
      </Rectangle.Triggers>
    </Rectangle>
 
    <Rectangle 
      Width="200" Height="200" Margin="10"
      Stroke="Black" StrokeThickness="1">
      <Rectangle.Fill>
        <DrawingBrush 
          Drawing="{StaticResource CheckerDrawing}"
          Viewport="0,0,50,50" 
          ViewportUnits="Absolute"
          TileMode="Tile">
          <DrawingBrush.RelativeTransform>
            <TransformGroup>
              <RotateTransform 
                x:Name="AnimatedRotateTransform2"
                CenterX="0.5" CenterY="0.5" />
              <ScaleTransform
                x:Name="AnimatedScaleTransform2"
                CenterX="0.5" CenterY="0.5" />
            </TransformGroup>
          </DrawingBrush.RelativeTransform>
        </DrawingBrush> 
      </Rectangle.Fill>
      <Rectangle.Triggers>
        <EventTrigger RoutedEvent="Rectangle.Loaded">
          <BeginStoryboard>
          
            <!-- The animations that belong to this storyboard
                 will run at full speed. -->
            <Storyboard>
              <DoubleAnimation 
                Storyboard.TargetName="AnimatedRotateTransform2"
                Storyboard.TargetProperty="Angle"
                From="0" To="360" 
                Duration="0:1:00" 
                AutoReverse="True"
                RepeatBehavior="Forever"
                />
              <DoubleAnimation 
                Storyboard.TargetName="AnimatedScaleTransform2"
                Storyboard.TargetProperty="ScaleX"
                From="1" To="5" 
                Duration="0:0:30" 
                AutoReverse="True"
                RepeatBehavior="Forever"
                />
              <DoubleAnimation 
                Storyboard.TargetName="AnimatedScaleTransform2"
                Storyboard.TargetProperty="ScaleY"
                From="1" To="5" 
                Duration="0:0:45" 
                AutoReverse="True"
                RepeatBehavior="Forever"
                />               
            </Storyboard>
          </BeginStoryboard>
        </EventTrigger>
      </Rectangle.Triggers>      
    </Rectangle> 
  
  
  </StackPanel>
  
    


</Page>

Observações

Use esta propriedade para definir uma taxa de fotogramas específica à qual as animações devem ser executadas. Isto é apenas uma diretriz e não é um valor garantido. Esta propriedade tem dois usos principais:

  • Limitar a quantidade de recursos de processamento para animações de fundo lentas que não exigem um elevado grau de fidelidade. Isto pode ser conseguido definindo um valor de taxa de fotogramas pequeno na linha temporal.

  • Reduzir o impacto visual do tearing em animações horizontais rápidas. Isto pode ser conseguido definindo um valor elevado de taxa de fotogramas na linha temporal.

Esta propriedade só pode ser definida numa linha temporal raiz.

Aplica-se a

Ver também

  • Visão geral da animação