WPF VB.Net

    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="Simple Animation" Height="165" Width="428">
  
    
    
      Start
      Stop
      
        
          
            
                              Storyboard.TargetProperty="Width" 
                From="50" To="300" Duration="0:0:2" RepeatBehavior="Forever" />