See http://msdn.microsoft.com/msdnmag/issues/07/10/WPFThreading/default.aspx

Jon

Take a look at the Dispatcher.Invoke method in System.Windows.Threading.

Willy.

In WPF you should use the Dispatcher Property to start any async
operations.
See the following example the variable _lbl is a label of my form.

       public partial class Window1 : System.Windows.Window
    {
        private Timer _timer = new Timer(1000);

        private delegate void DummyDelegate();

        public Window1()
        {
            InitializeComponent();
            _timer.Elapsed += delegate
            {
                this.Dispatcher.Invoke(
                    System.Windows.Threading.DispatcherPriority.Normal,
(DummyDelegate)
                    delegate { _lbl.Content = DateTime.Now.ToLongTimeString(); });
            };
            _timer.Start();
        }

    }

Hi Jon, Willy, Roman,

Thanks for your hints. I have my little app working now.

Regards
Rainer