Take a look at ClippingBehavior , which is part of the Expression Blend samples on CodePlex. This is the Blend behavior, so to add it you need to refer to the System.Windows.Interactivity.dll from the Blend SDK and drop the element's behavior in Blend or add it to XAML:
<UserControl x:Class="MyApplication.MainPage" ...other xmlns imports... xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity" xmlns:samples="clr-namespace:Expression.Samples.Interactivity;assembly=Expression.Samples.Interactivity" > <Border> <i:Interaction.Behaviors> <samples:ClippingBehavior CornerRadius="15"/> </i:Interaction.Behaviors> </Border> </UserControl>
This is a simple and reusable way to add rounded corners / crop to any user interface element.
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