protected override void OnStartDemo(IViewport viewport) { IUIRootElement root = viewport.Root; IUIBoxElement sampleButton = (IUIBoxElement)root.CreateElement2(BasicUIElementKind.SimpleBox); root.AddContent(sampleButton); sampleButton.SetLocation(20, 20); IUIBoxElement textbox = (IUIBoxElement)root.CreateElement2(BasicUIElementKind.TextBox); root.AddContent(textbox); textbox.SetLocation(20, 60); textbox.SetSize(100, 24); IUIEventListener evListener = root.CreateEventListener(); int count = 0; evListener.MouseDown += (e) => { System.Console.WriteLine("click :" + (count++)); }; sampleButton.AttachEventListener(evListener); }