CentralMonitor.Window1.OnClosed C# (CSharp) Method

        protected override void OnClosed(EventArgs e) {
            new XDocument(
                new XElement("tools",
                    from tool in service.Tools
                    select new XElement("tool",
                        new XAttribute("id", tool.Id),
                        new XAttribute("url", tool.Url),
                        new XAttribute("regtime", tool.RegisiterTime))))
            .Save(TOOLS_XML_FILE);
        }