使用 XML 反化时出现错误：

　　　　　public static TResult GetObjectFromXml<TResult>(string xmlString)        {            TResult result;            XmlSerializer serializer = new XmlSerializer(typeof(TResult), new XmlRootAttribute("xml"));            using (TextReader tr = new StringReader(xmlString))            {                                result = (TResult)serializer.Deserialize(tr);            }            return result;        }

要使结果正确，必须满足两个条件中的任意一个：
1. TResult 类的类名称和 XML 根元素名一致。
2. 若类名和根元素名称不一致，在初始化 XmlSerializer 时传入第二个参数，new XmlRootAttribute("【根元素名称】")，以指定根元素名称

否则 Xmlserializer.Deserialize 抛出如下异常：

System.InvalidOperationException: There is an error in XML document (1, 2). ---> System.InvalidOperationException: <xml xmlns=‘‘> was not expected.
Result StackTrace:
at Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationReaderTResult.Read3_RootElementName()

at System.Xml.Serialization.XmlSerializer.Deserialize(XmlReader xmlReader, String encodingStyle, XmlDeserializationEvents events)
at System.Xml.Serialization.XmlSerializer.Deserialize(TextReader textReader)