<add key="SaveXmlPath" value="D:\SaveXml.xml"/>

 public class SingleResultBE
    {
        public string Id { get; set; }
        public string Operation { get; set; }
    }

        private void SavelistToxml(List<SingleResultBE> listInsertResult)
        {
            string saveName = ConfigurationManager.AppSettings["SaveXmlPath"];
           
            XElement XmlSaveResult =new XElement("SaveResult",
                        from entity in HavelistResult
                        select new XElement("Result",
                        new XAttribute("ID", string.IsNullOrEmpty(entity.Id)?"1":entity.Id),
                        new XAttribute("Operation", string.IsNullOrEmpty(entity.Operation) ? "1" : entity.Operation)
                        )
                        );
            XmlSaveResult.Save(saveName);
        }

private list<SingleResultBE> ReadxmlForList()
        {
        
            string xmlName = ConfigurationManager.AppSettings["SaveXmlPath"];
                 XElement docxml = XElement.Load(xmlName);
                List<SingleResultBE> listHaveInsert = (from entity in docxml.Elements()
                                               select entity).ToList();
             return listHaveInsert;
        }