public void Update(Setting setting)
 {
     var doc = GetDoc();
     var ele = doc.Root.Element("settings").Elements().Where(x => x.Attribute(XName.Get("key")).Value == setting.Key).First();
     ele.Value = setting.Value;
     doc.Save(xmlfile);
 }
 public void Insert(Setting setting)
 {
     var doc = GetDoc();
     XElement ele = new XElement("setting");
     ele.Add(new XAttribute("key", setting.Key));
     ele.Value = setting.Value;
     doc.Root.Element(XName.Get("settings")).Add(ele);
     doc.Save(xmlfile);
 }