Change border
<Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" x:Class="AboutDialog" MouseRightButtonDown="AboutDialog_MouseRightButtonDown" Title="About WPF Unleashed" SizeToContent="WidthAndHeight" Background="OrangeRed"> <StackPanel> <Label FontWeight="Bold" FontSize="20" Foreground="White"> WPF </Label> <Label>License</Label> <Label>Installed Dll:</Label> <ListBox> <ListBoxItem>1</ListBoxItem> <ListBoxItem>2</ListBoxItem> <ListBoxItem>3</ListBoxItem> <ListBoxItem>4</ListBoxItem> <ListBoxItem>5</ListBoxItem> <ListBoxItem>6</ListBoxItem> <ListBoxItem>7</ListBoxItem> <ListBoxItem>8</ListBoxItem> <ListBoxItem>9</ListBoxItem> </ListBox> <StackPanel Orientation="Horizontal" HorizontalAlignment="Center"> <Button MinWidth="75" Margin="10">Help</Button> <Button MinWidth="75" Margin="10">OK</Button> </StackPanel> <StatusBar>test</StatusBar> </StackPanel> </Window> //File:Window.xaml.cs using System; using System.Windows; using System.Windows.Input; using System.Windows.Media; using System.Windows.Controls; public partial class AboutDialog : Window { public AboutDialog() { InitializeComponent(); } void AboutDialog_MouseRightButtonDown(object sender, MouseButtonEventArgs e) { Console.WriteLine("Source = " + e.Source.GetType().Name); Console.WriteLine("OriginalSource = " + e.OriginalSource.GetType().Name + " @ " + e.Timestamp); Control source = e.Source as Control; if (source.BorderThickness != new Thickness(5)) { source.BorderThickness = new Thickness(5); source.BorderBrush = Brushes.Black; } else source.BorderThickness = new Thickness(0); } }