Timeline.DesiredFrameRate 附加属性

定义

命名空间:

System.Windows.Media.Animation

程序集:

PresentationCore.dll

获取或设置此时间线及其子时间线所需的帧速率。

see GetDesiredFrameRate, and SetDesiredFrameRate

see GetDesiredFrameRate, and SetDesiredFrameRate

see GetDesiredFrameRate, and SetDesiredFrameRate

示例

以下示例使用 DesiredFrameRate 属性将多个动画限制为每秒 10 帧。

<!-- 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>

注解

使用此属性可定义应运行动画的特定帧速率。这只是一个准则，不是一个保证的值。 此属性有两个主要用途：

• 限制低速移动的背景类型动画的处理资源量，这些动画不需要高度保真度。 可以通过在时间线上设置较小的帧速率值来实现此目的。

• 减少撕裂对快速移动水平动画的视觉影响。 可以通过在时间线上设置高帧速率值来实现此目的。

此属性只能在根时间线上设置。

另请参阅

• 动画概述