用程序修改配置文件

        [HttpPost]        public ActionResult SaveSetting(string key, string value)        {            if (!string.IsNullOrWhiteSpace(key) && !string.IsNullOrWhiteSpace(value)                && ConfigurationManager.AppSettings.AllKeys.Contains(key))            {                //ConfigurationManager.AppSettings.Set(key, value);                                                //var config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);  //winform之类应用程序的修改方式                var config = WebConfigurationManager.OpenWebConfiguration("~");  //web应用程序修改                config.AppSettings.Settings[key].Value = value;                config.Save();            }            return RedirectToAction("Index");        }