How to: Seek a Storyboard

<Page xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
  	x:Class="SDKSample.SeekStoryboardExample">
  <StackPanel Margin="20" >

    <Rectangle Name="myRectangle"
      Width="10" Height="20" Fill="#AA3333FF" HorizontalAlignment="Left" >
      <Rectangle.Triggers>
        <EventTrigger RoutedEvent="Rectangle.Loaded">
          <BeginStoryboard Name="myBeginStoryboard">
            <Storyboard Name="myStoryboard" Duration="0:0:4">
              <DoubleAnimation 
                Storyboard.TargetName="myRectangle" 
                Storyboard.TargetProperty="Width" 
                Duration="0:0:4" From="10" To="500"/>
            </Storyboard>

          </BeginStoryboard>
        </EventTrigger>
      </Rectangle.Triggers>
    </Rectangle>

    <!-- Use this slider to seek to different points of the Storyboard Duration 
         (in milliseconds). -->
    <Slider Name="SeekSlider" ValueChanged="OnSliderValueChanged" Height="Auto" 
    Width="500" Minimum="0" Maximum="4000" HorizontalAlignment="Left" />

  </StackPanel>
</Page>

using System;
using System.Media;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media.Animation;

namespace SDKSample
{

    public partial class SeekStoryboardExample : Page
    {
        private void OnSliderValueChanged(object sender, RoutedEventArgs e)
        {
            int sliderValue = (int)SeekSlider.Value;

            // Use the value of the slider to seek to a duration value of the Storyboard (in milliseconds).
            myStoryboard.Seek(myRectangle, new TimeSpan(0, 0, 0, 0, sliderValue), TimeSeekOrigin.BeginTime);
        }
    }

}