Attributes

Name	Use
CornerRadius	Set border fillet values
Circular	Whether it is rendered as a circle True is Yes, False is No

Use Cases

CornerRadius Set the border fillet value

<StackPanel Width="200" VerticalAlignment="Center">
    <Button Content="Button" hc:BorderElement.CornerRadius="15" HorizontalAlignment="Stretch"/>
    <TextBox Text="TextBox" hc:BorderElement.CornerRadius="15" Margin="0,10,0,0"/>
</StackPanel>

Circular

Implement a circular border with the attached property of BorderElement.Circular

<Border Style="{StaticResource BorderCircular}" Background="OrangeRed" Width="100" Height="100"/>