<Page xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
      HorizontalAlignment="Stretch" VerticalAlignment="Stretch">

<StackPanel Orientation="Horizontal" VerticalAlignment="Center">
  <StackPanel.Triggers>
    <EventTrigger RoutedEvent="StackPanel.Loaded">
      <BeginStoryboard>
        <Storyboard RepeatBehavior="Forever">

<!-- Example 16-17. Implicit duration of parent timeline -->

<ParallelTimeline>

  <DoubleAnimation BeginTime="0:0:0" Duration="0:0:0.2"
        Storyboard.TargetName="button1"
        Storyboard.TargetProperty="(Button.Height)"
        By="30" />

  <DoubleAnimation BeginTime="0:0:1" Duration="0:0:0.2"
        Storyboard.TargetName="button2"
        Storyboard.TargetProperty="(Button.Height)"
        By="30" />

</ParallelTimeline>

<!-- End of Example 16-17. -->

        </Storyboard>
      </BeginStoryboard>
    </EventTrigger>
  </StackPanel.Triggers>

  <Button Name="button1" Height="25">One</Button>
  <Button Name="button2" Height="25">Two</Button>
  <Button Name="button3" Height="25">Three</Button>
  <Button Name="button4" Height="25">Four</Button>
</StackPanel>

</Page>
