XmlReader 访问远程XML 的权限设置问题（401错误解决办法）

                XmlUrlResolver resolver = new XmlUrlResolver();
                resolver.Credentials = System.Net.CredentialCache.DefaultCredentials;

                XmlReaderSettings settings = new XmlReaderSettings();
                settings.XmlResolver = resolver;

                string url = "http://localhost:8888/hy/HyServer/GetEverydayMenu.aspx?userName=" + userName + "&sessionID=" + sessionID;
                XmlReader reader = XmlReader.Create(url, settings);