public MainWindow() { InitializeComponent(); var updatesWebService = new UpdatesWebService(); _subscription = Observable .Interval(TimeSpan.FromSeconds(3)) .Take(3) // we dont want to run the example forever, so we'll do only 3 updates .SelectMany(_ => updatesWebService.GetUpdatesAsync()) .SelectMany(updates => updates) .ObserveOnDispatcher() .Subscribe(message => messages.Items.Add(message)); }