<Window x:Class="WpfApplication1.Window1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="Window1" Height="300" Width="300"> <StackPanel> <TextBox x:Name="uv" Text="{Binding Path=UserValue, UpdateSourceTrigger=PropertyChanged}" /> </StackPanel> </Window> //File:Window1.xaml.cs using System.Windows; using System.Windows.Controls; using System.Windows.Media; namespace WpfApplication1 { public partial class Window1 : Window { public Window1() { InitializeComponent(); DataContext = this; } private static void UserValue_PropertyChangedCallback(DependencyObject d, DependencyPropertyChangedEventArgs e) { Window1 window1 = d as Window1; if (window1 != null) { window1.uv.Foreground = Brushes.SeaGreen; } } } }