//File:Window.xaml.cs using System; using System.Collections.Generic; using System.Text; using System.Windows; using System.Windows.Controls; using System.Windows.Data; using System.Windows.Documents; using System.Windows.Input; using System.Windows.Media; using System.Windows.Media.Imaging; using System.Windows.Shapes; namespace VisualTree { public partial class Window1 : System.Windows.Window { public Window1() { InitializeComponent(); } void MyClickEvent(object sender, RoutedEventArgs e) { object desiredNode = btnGo.FindName("txt"); if (desiredNode is TextBox) { TextBox desiredChild = desiredNode as TextBox; desiredChild.Background = Brushes.Green; } } } }