如何?类对象的XML序列化

我正在尝试序列化Class对象并将xml存储在字符串中，但是每次收到异常消息生成xml文档时出错"

我要序列化的类对象属于类:

I am trying to Serialize a Class object and store the xml in a string but each time I get an exception message "There was an error generating xml document"

The class object I am trying to serialize is of class:

[XmlRoot("FlowOfTask")] 
    public class Flow
    {
        int _CurrHop = 0;

        [XmlElement("CurrentHop")]
        public int CurrentHop
        {
            get { return _CurrHop; }
            set { _CurrHop = value; }
        }
        
        int _TotalHops = 0;

        [XmlElement("TotalHops")]
        public int TotalHops
        {
            get { return _TotalHops; }
        }
        
        private List<tblTaskHop> _TaskHops;

        [System.Xml.Serialization.XmlArrayItemAttribute(ElementName = "Hop",
        IsNullable = false)]
        public List<tblTaskHop> TaskHops
        {
            get { return _TaskHops; }
        }
        public Flow()
        {

        }

        public Flow(Int64 TaskID, Int64 RoleID)
        {
            _TaskHops = HandleDB.tblTaskHopGetByTaskIDRoleID(TaskID, RoleID);
            _TotalHops = TaskHops.Count;
        }

    }

我正在使用此功能进行序列化.

I am using this function to serialize.

public static string SerializeAnObject(object item)
        {

            try
            {
                string xmlText;

                //Get the type of the object
                Type objectType = item.GetType();

                //create serializer object based on the object type
                XmlSerializer xmlSerializer = new XmlSerializer(objectType);

                //Create a memory stream handle the data
                MemoryStream memoryStream = new MemoryStream();

                //Create an XML Text writer to serialize data to
                using (XmlTextWriter xmlTextWriter =
                    new XmlTextWriter(memoryStream, Encoding.UTF8) { Formatting = Formatting.Indented })
                {

                    //convert the object to xml data
                    xmlSerializer.Serialize(xmlTextWriter, item);

                    //Get reference to memory stream
                    memoryStream = (MemoryStream)xmlTextWriter.BaseStream;

                    //Convert memory byte array into xml text
                    xmlText = new UTF8Encoding().GetString(memoryStream.ToArray());

                    //clean up memory stream
                    memoryStream.Dispose();
                    return xmlText;
                }
            }
            catch (Exception e)
            {
                MessageBox.Show(e.Message);
                return null;
            }
        }

谁能帮我为什么我不能序列化该类对象?

Can anyone help me why I am not able to serialize this class object?