x:Class="Main"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title=""
Height="130"
Width="200">
x:Key="StringAnimationStoryboard">
AutoReverse="True"
Storyboard.TargetName="MyTextBox"
Storyboard.TargetProperty="Text">
x:Name="MyTextBox"
DockPanel.Dock="Top"
FontSize="30"
Margin="5" HorizontalAlignment="Center" />
Content="Start Animation"
Width="100"
Height="20">
RoutedEvent="Button.Click">
Storyboard="{DynamicResource StringAnimationStoryboard}" />