讀取配置文件並修改

1. 讀取某個文件夾下的Web.config中的appSection的節點，並修改保存

Configuration config = WebConfigurationManager.OpenWebConfiguration("~/rmsms");
            AppSettingsSection appSection = (AppSettingsSection)config.GetSection("appSettings");
            appSection.Settings["FCKeditor:UserFilesPath"].Value = "D:";
            config.Save(ConfigurationSaveMode.Modified);