<Page xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" HorizontalAlignment="Stretch" VerticalAlignment="Stretch"> <Button Width="20" Height="20"> <Button.Triggers> <EventTrigger RoutedEvent="Rectangle.Loaded"> <BeginStoryboard> <Storyboard> <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="(Button.Visibility)"> <DiscreteObjectKeyFrame KeyTime="0:0:1.5"> <DiscreteObjectKeyFrame.Value> <Visibility>Hidden</Visibility> </DiscreteObjectKeyFrame.Value> </DiscreteObjectKeyFrame> </ObjectAnimationUsingKeyFrames> </Storyboard> </BeginStoryboard> </EventTrigger> </Button.Triggers> </Button> </Page>