The dash style of a line is specified by the StrokeDashArray property that gets or sets a collection of double variables
<Window x:Class="ScaleInCustomSystem" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="Scale In Custom System" Height="310" Width="260"> <StackPanel Height="280" Width="250"> <Line X1="30" Y1="50" X2="250" Y2="50" Stroke="Blue" StrokeThickness="2" StrokeDashArray="5,3" /> </StackPanel> </Window>