#229 – Using a Gradient Brush for a Window’s Border

The Window class has BorderBrush and BorderThickness properties that allow creating a thick border around the window’s client area.  (Just inside the standard window chrome).

You can use any brush you like as a border brush.  In the example below, we use a linear gradient brush that starts in the upper left corner of the window and cycles through the colors of the rainbow until it reaches the lower right corner of the window.  Note that we set the BorderThickness to 10.

<Window
	xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
	xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
	xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
	xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
	mc:Ignorable="d"
	xmlns:local="clr-namespace:WpfApplication1"
    xmlns:sys="clr-namespace:System;assembly=mscorlib"
    x:Class="WpfApplication1.MainWindow"
	x:Name="Window"
	Title="Rainbow Border"
	BorderThickness="10">

	<Window.BorderBrush>
		<LinearGradientBrush StartPoint="0,0" EndPoint="1,1">
		    <GradientStop Color="Red" Offset="0.0"/>
		    <GradientStop Color="Orange" Offset="0.17"/>
		    <GradientStop Color="Yellow" Offset="0.33"/>
		    <GradientStop Color="Green" Offset="0.5"/>
		    <GradientStop Color="Blue" Offset="0.67"/>
		    <GradientStop Color="Indigo" Offset="0.83"/>
		    <GradientStop Color="Violet" Offset="1.0"/>
		</LinearGradientBrush>
	</Window.BorderBrush>

	<StackPanel VerticalAlignment="Center">
		<Button Content="Click Me" Width="100" Margin="10"/>
		<Label Content="I'm a label, you know" HorizontalAlignment="Center" Margin="10"/>
	</StackPanel>
</Window>