<StackPanel xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" x:Class="WpfApplication1.RoutedEventSource"> <StackPanel.Resources> <Style TargetType ="{x:Type Button}"> <Setter Property="Height" Value="30"/> <Setter Property="Width" Value="100"/> <Setter Property="HorizontalAlignment" Value="Left"/> </Style> </StackPanel.Resources> <Button Click="HandleClick">Button 1</Button> <Button Click="HandleClick">Button 2</Button> <Button Click="HandleClick">Button 3</Button> </StackPanel> //File:Window.xaml.cs using System.Windows; using System.Windows.Controls; namespace WpfApplication1 { public partial class RoutedEventSource { void HandleClick(object sender, RoutedEventArgs e) { Button srcButton = e.Source as Button; srcButton.Width = 200; } } }