# Timeline.SpeedRatio Property

## Definition

Gets or sets the rate, relative to its parent, at which time progresses for this Timeline.

``````public:
property double SpeedRatio { double get(); void set(double value); };``````
``public double SpeedRatio { get; set; }``
``member this.SpeedRatio : double with get, set``
``Public Property SpeedRatio As Double``

#### Property Value

Double

A finite value greater than 0 that describes the rate at which time progresses for this timeline, relative to the speed of the timeline's parent or, if this is a root timeline, the default timeline speed. The default value is 1.

#### Exceptions

SpeedRatio is less than 0 or is not a finite value.

## Examples

A timeline's SpeedRatio property controls its rate of progress, relative to its parent. If the timeline is a root, its SpeedRatio is relative to the default timeline speed. The following example shows several timelines with different SpeedRatio settings.

``````<!-- This example shows how to use the SpeedRatio property
to make animations speed up or slow down. -->
<Page
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
WindowTitle="Speed Example">
<StackPanel>

<!-- The rectangles to animate. -->
<Rectangle Name="DefaultSpeedRectangle"
Width="20" Height="20" Fill="Blue"  />
<Rectangle Name="FasterRectangle"
Width="20" Height="20" Fill="Blue" />
<Rectangle Name="SlowerRectangle"
Width="20" Height="20" Fill="Blue" />
<Rectangle Name="NestedTimelinesExampleRectangle"
Width="20" Height="20" Fill="Blue" />

<!-- Create a button to start the animations. -->
<Button Margin="0,30,0,0" HorizontalAlignment="Left">Start Animations
<Button.Triggers>
<EventTrigger RoutedEvent="Button.Click">
<BeginStoryboard>
<Storyboard>

<!-- This animation progresses at the same rate as its parent. -->
<DoubleAnimation
Storyboard.TargetName="DefaultSpeedRectangle"
Storyboard.TargetProperty="Width"
From="20" To="400" Duration="0:0:2"
SpeedRatio="1" />

<!-- This animation progresses twice as fast as its parent. -->
<DoubleAnimation
Storyboard.TargetName="FasterRectangle"
Storyboard.TargetProperty="Width"
From="20" To="400" Duration="0:0:2"
SpeedRatio="2"  />

<!-- This animation progresses at half the rate of its parent. -->
<DoubleAnimation
Storyboard.TargetName="SlowerRectangle"
Storyboard.TargetProperty="Width"
From="20" To="400" Duration="0:0:2"
SpeedRatio="0.5"  />

<ParallelTimeline SpeedRatio="2">
<ParallelTimeline SpeedRatio="2">

<!-- This animation progresses eight times faster
than normal, because of its SpeedRatio settings
and the SpeedRatio settings on its parents. -->
<DoubleAnimation
Storyboard.TargetName="NestedTimelinesExampleRectangle"
Storyboard.TargetProperty="Width"
From="20" To="400" Duration="0:0:2"
SpeedRatio="2"  />
</ParallelTimeline>
</ParallelTimeline>
</Storyboard>
</BeginStoryboard>
</EventTrigger>
</Button.Triggers>
</Button>
</StackPanel>
</Page>
``````

## Remarks

A timeline's SpeedRatio setting does not have an effect on its BeginTime; that time is relative to the timeline's parent or, if the timeline is a root timeline, the moment at which the timeline's clock was begun.

If AccelerationRatio or DecelerationRatio are specified, this SpeedRatio is the average ratio over the natural length of the timeline.

### Dependency Property Information

Identifier field SpeedRatioProperty
Metadata properties set to `true` None