Gradient brushes within a DrawingBrush
<Window x:Class="Workspace.DockExample" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="Workspace" Width="640" Height="480"> <Rectangle Width="50" Height="50" Grid.Row="2" Grid.Column="1"> <Rectangle.Fill> <VisualBrush> <VisualBrush.Visual> <StackPanel Background="White"> <Button Margin="1">A Button</Button> <Button Margin="1">Another Button</Button> </StackPanel> </VisualBrush.Visual> </VisualBrush> </Rectangle.Fill> </Rectangle> </Window>