[Serializable]
    public class Field : ISerializable
    {
        private string name = "";
        private DataRow dr = null;
        private string title = "";
        private int index = -1;

        public int Index
        {
            get { return this.index; }
            set { this.index = value; }
        }

        public string Title
        {
            get { return this.title; }
            set { this.title = value; }
        }

        public string FieldName
        {
            get { return this.name; }
            set { this.name = value; }
        }

        public DataRow FieldInfo
        {
            get { return this.dr; }
            set { this.dr = value; }
        }

        public Field()
        {
            DataTable dt = new DataTable();
            dt.Columns.Add("name");
            this.dr = dt.NewRow();
            dt.Rows.Add(dr);
          
        }

        protected Field(SerializationInfo info, StreamingContext context)//特殊的构造函数，反序列化时自动调用
        {
            this.name = info.GetString("fieldname");
            this.title = info.GetString("fieldtitle");
            this.index = info.GetInt32("fieldindex");
            DataTable dt = info.GetValue("fieldinfo", new DataTable().GetType()) as DataTable;
            this.dr = dt.Rows[0];
        }

        [SecurityPermissionAttribute(SecurityAction.Demand, SerializationFormatter = true)]
        public virtual void GetObjectData(SerializationInfo info, StreamingContext context)//序列化时自动调用
        {
            info.AddValue("fieldname", this.name);
            info.AddValue("fieldtitle", this.title);
            info.AddValue("fieldindex", this.index);
            DataTable dt = this.dr.Table.Clone(); //datarow不能同时加入到两个DataTable中，必须先克隆一个
            DataRow row = dt.NewRow();
            row.ItemArray = dr.ItemArray;

            dt.Rows.Add(row);
            info.AddValue("fieldinfo", dt, dt.GetType());
        }

    }