<Window x:Class="LineInDefaultSystem" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="Line in Default System" Height="300" Width="300"> <Canvas Height="300" Width="300"> <Line X1="0" Y1="0" X2="100" Y2="100" Stroke="Black" StrokeThickness="2" /> </Canvas> </Window>