<Window x:Class="Main" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="" Height="300" Width="300"> <Grid> <Rectangle Height="100" Width="100" Fill="Firebrick" Stroke="Black" StrokeThickness="1"> <Rectangle.Style> <Style TargetType="Rectangle"> <Style.Triggers> <EventTrigger RoutedEvent="Rectangle.MouseEnter"> <BeginStoryboard> <Storyboard> <ParallelTimeline RepeatBehavior="Forever" AutoReverse="True"> <DoubleAnimation Storyboard.TargetProperty="Width" To="150" /> <DoubleAnimation Storyboard.TargetProperty="Height" To="150" /> <ColorAnimation Storyboard.TargetProperty="Fill.Color" To="Orange" /> </ParallelTimeline> </Storyboard> </BeginStoryboard> </EventTrigger> </Style.Triggers> </Style> </Rectangle.Style> </Rectangle> </Grid> </Window>