c#如何写xml config文件

File.Create(Application.StartupPath + ("\\Setting.config"));
在创建完config文件后如何写操作这个文件？
例如写入：
<?xml version="1.0" encoding="utf-8"?>

---

就当普通文件操作就好
file。open
然后filestream。write

---

FileStream newfile = null;
            if (!File.Exists(Application.StartupPath + "\\Setting.config"))
            {
                newfile = new FileStream(Application.StartupPath + "\\Setting.configt", FileMode.Create, FileAccess.Write);
            }
            else
            { 
                newfile = new FileStream(Application.StartupPath + "\\Setting.config", FileMode.Truncate, FileAccess.Write);
            }
            StreamWriter sw = new StreamWriter(newfile);
            sw.Write(" <?xml version="1.0" encoding="utf-8"?> ");
            sw.Close();
            newfile.Close();