<Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:src="clr-namespace:MyNameSpace.DigitalClock" Title="Digital Clock" SizeToContent="WidthAndHeight"> <Window.Resources> <src:ClockTicker1 x:Key="clock" /> </Window.Resources> <Window.Content> <Binding Source="{StaticResource clock}" Path="DateTime" /> </Window.Content> </Window> //File:Window.xaml.cs using System; using System.Windows; using System.Windows.Threading; namespace MyNameSpace.DigitalClock { public class ClockTicker1 : DependencyObject { public static DependencyProperty DateTimeProperty = DependencyProperty.Register("DateTime", typeof(DateTime), typeof(ClockTicker1)); public DateTime DateTime { set { SetValue(DateTimeProperty, value); } get { return (DateTime) GetValue(DateTimeProperty); } } public ClockTicker1() { DispatcherTimer timer = new DispatcherTimer(); timer.Tick += TimerOnTick; timer.Interval = TimeSpan.FromSeconds(1); timer.Start(); } void TimerOnTick(object sender, EventArgs args) { DateTime = DateTime.Now; } } }