public void AddAfterSelectedBoxes(IEnumerable <TessBoxControl> selectedBoxes) { var box = selectedBoxes.LastOrDefault(); if (box != null) { var pos = Boxes.IndexOf(box); var newBox = new TessBoxControl() { Width = box.Width, Height = box.Height, Value = "n" }; Canvas.SetLeft(newBox, box.Left + box.Width); Canvas.SetTop(newBox, box.Top); Boxes.Insert(pos + 1, newBox); } }