用NET自带的XML序列化工具进行系列化和反序列化；

需要引用的命名空间：

using System.Xml;
using System.Xml.Serialization;

XmlSerializer serializer = new XmlSerializer(typeof(Student));
            using (FileStream stream = new FileStream(path, FileMode.OpenOrCreate))
            {
                serializer.Serialize(stream, student);
            }

对核心代码制作的数据流程图，以便于理解数据流向和工作原理；

serializer.Serialize(stream, student);

窗口设计

测试用学生类

 public class Student
    {
        private string m_Name;
        private string m_Sex;
        private int m_Age;

        public string Name { get => m_Name; set => m_Name = value; }
        public string Sex { get => m_Sex; set => m_Sex = value; }
        public int Age { get => m_Age; set => m_Age = value; }


        public string Say() { return $"my name is {Name}"; }
    }

将学生类进行序列化，并保存至XML文件，测试读取XML文件内容

string path = Application.StartupPath + @"\data.xml";
        Student student = new Student() { Name = "孙悟空", Sex = "男", Age = 5000 };
        /// <summary>
        /// 序列化,并读取XML
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button1_Click(object sender, EventArgs e)
        {
            listBox1.Items.Clear();
            XmlSerializer serializer = new XmlSerializer(typeof(Student));
            using (FileStream stream = new FileStream(path, FileMode.OpenOrCreate))
            {
                serializer.Serialize(stream, student);
            }
            XmlDocument doc = new XmlDocument();
            if (File.Exists(path)) doc.Load(path);
            else return;
            XmlNode root = doc.DocumentElement;
            listBox1.Items.Add(root.InnerText);
            bool b = root.HasChildNodes;
            listBox1.Items.Add("root.HasChildNodes?"+b);
            XmlNodeList list= root.ChildNodes;
            listBox1.Items.Add("子节点个数?" + list.Count);
            foreach (XmlNode item in list)
            {
                listBox1.Items.Add(item.InnerText);
            }

        }

点击加载按钮--加载XML文件并进行反序列化

/// <summary>
        /// 加载XML，反序列化
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button2_Click(object sender, EventArgs e)
        {
            if (!File.Exists(path)) return;
            XmlSerializer serializer = new XmlSerializer(typeof(Student));
            using (FileStream stream = new FileStream(path, FileMode.Open))
            {
                Student student2 = serializer.Deserialize(stream) as Student;
                listBox1.Items.Clear();
                listBox1.Items.Add("反序列化数据");
                listBox1.Items.Add("生成类型"+student2.ToString());
                listBox1.Items.Add(student2.Name);
                listBox1.Items.Add(student2.Sex);
                listBox1.Items.Add(student2.Age);
                listBox1.Items.Add("Say()" + student2.Say());
            }

        }

结果：