public static void WriteOff(List <XElement> elements) { var checkOff = new CheckType(GetBarCodeCheck(), 0, 0, 0, 0, 0, 0, 0, DateTime.Now); var number = 0; foreach (var element in elements) { var product = ProductType.FromCheckXElement(element); product.Ii = number++; checkOff.Products.Add(product); } GetDucument(); var checksElement = Document.GetXElement("checks"); checksElement.Add(CheckType.ToXElement(checkOff)); Document.Save(Path); }