实在不行,就先用初始化一个文件,然后再序序化
try
            {
               
                if (!File.Exists("文件路径"))
                {
                    XmlTextWriter writer = new XmlTextWriter("文件路径", null);
                    writer.Formatting = Formatting.Indented;
                    writer.Indentation = 4;
                    writer.WriteStartDocument();
                    writer.WriteStartElement("DevToolUserConfig");
                    writer.WriteEndElement();
                    writer.WriteEndDocument();
                    writer.Flush();
                    writer.Close();
                }
            }
            catch
            {