<Window x:Class="AnimationSpeed"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="Animation Speed Example" Height="240" Width="410">
<StackPanel Margin="5">
<Rectangle Name="rect3" Fill="Blue" Margin="2" Width="20"
Height="20" HorizontalAlignment="Left" />
<Button Margin="2,20,0,0" HorizontalAlignment="Left"
Content="Start Animations" Width="100">
<Button.Triggers>
<EventTrigger RoutedEvent="Button.Click">
<EventTrigger.Actions>
<BeginStoryboard>
<Storyboard>
<DoubleAnimation
Storyboard.TargetName="rect3" Storyboard.TargetProperty="Width"
From="20" To="400" Duration="0:0:10" SpeedRatio="0.5" />
</Storyboard>
</BeginStoryboard>
</EventTrigger.Actions>
</EventTrigger>
</Button.Triggers>
</Button>
</StackPanel>
</Window>