<Window.Resources>
<ControlTemplate x:Key="ProgressBarControlTemplate1" TargetType="{x:Type ProgressBar}">
<ControlTemplate.Resources>
<Storyboard x:Key="OnLoaded1" RepeatBehavior="Forever">
<DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.RenderTransform).
(TransformGroup.Children)[2].(RotateTransform.Angle)" Storyboard.TargetName="ellipse">
<EasingDoubleKeyFrame KeyTime="0" Value="-180"/>
<EasingDoubleKeyFrame KeyTime="0:0:0.5" Value="180"/>
</DoubleAnimationUsingKeyFrames>
</Storyboard>
</ControlTemplate.Resources>
<Grid>
<Ellipse x:Name="ellipse" Height="Auto" Margin="0" VerticalAlignment="Stretch" Width="Auto"
RenderTransformOrigin="0.5,0.5" >
<Ellipse.RenderTransform>
<TransformGroup>
<ScaleTransform/>
<SkewTransform/>
<RotateTransform Angle="-90"/>
<TranslateTransform/>
</TransformGroup>
</Ellipse.RenderTransform>
<Ellipse.Stroke>
<LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
<GradientStop Color="#FF8878F0" Offset="0"/>
<GradientStop Color="#FFE9E8EA" Offset="0.992"/>
<GradientStop Color="#FFE9E8EA" Offset="0.356"/>
</LinearGradientBrush>
</Ellipse.Stroke>
</Ellipse>
</Grid>
<ControlTemplate.Triggers>
<EventTrigger RoutedEvent="FrameworkElement.Loaded">
<BeginStoryboard Storyboard="{StaticResource OnLoaded1}"/>
</EventTrigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Window.Resources>
