<StackPanel xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:d="http://schemas.microsoft.com/expression/interactivedesigner/2006" mc:Ignorable="d" x:Class="PaintDrawExamples.ChangeFill" Width="640" Height="480"> <StackPanel.Resources> <Storyboard x:Key="OnLoaded"/> </StackPanel.Resources> <StackPanel.Triggers> <EventTrigger RoutedEvent="FrameworkElement.Loaded"> <BeginStoryboard x:Name="OnLoaded_BeginStoryboard" Storyboard="{DynamicResource OnLoaded}"/> </EventTrigger> </StackPanel.Triggers> <Path d:LastTangent="0,0" Width="300" Height="82" x:Name="myShape" RenderTransformOrigin="0.5,0.5" Stretch="Fill" Data="M268,209 L134,209 147,249 250,290 z"> <Path.RenderTransform> <TransformGroup> <TranslateTransform X="0" Y="0"/> <ScaleTransform ScaleX="1" ScaleY="1"/> <SkewTransform AngleX="0" AngleY="0"/> <RotateTransform Angle="0"/> <TranslateTransform X="0" Y="0"/> </TransformGroup> </Path.RenderTransform> <Path.Fill> <LinearGradientBrush StartPoint="0,0.5" EndPoint="1,0.5"> <GradientStop Color="#11111111" Offset="0"/> <GradientStop Color="#FFFFFFFF" Offset="1"/> </LinearGradientBrush> </Path.Fill> </Path> </StackPanel> //File:Window.xaml.cs using System; using System.IO; using System.Net; using System.Windows; using System.Windows.Controls; using System.Windows.Data; using System.Windows.Input; using System.Windows.Media; using System.Windows.Media.Animation; using System.Windows.Navigation; namespace PaintDrawExamples { public partial class ChangeFill { public ChangeFill() { this.InitializeComponent(); this.MouseDown += new MouseButtonEventHandler(MouseDownHandler); } private void MouseDownHandler(object sender, MouseButtonEventArgs e) { LinearGradientBrush brush = (LinearGradientBrush)this.myShape.Fill; brush.GradientStops[0].Color = Color.FromRgb(0,0,0); } } }