C#｜更改序列化节点Name名及XElement返序列化

上一篇https://blog.huvjie.com/2020/11/28/201128N03/可以在原有的 xml 文档里添加一个序列化对象的元素节点。接的的 Name 名字默认的是对象类型名，如何更改这个名字呢？另外将一个 XElement 节点返序列化成一个对象。

1. 直接对 XElement 的 Name 属性赋值就能改名。
2. 将一个 XElement 节点返序列化，和从文档加载区别不大，注意将更改的 Name 属性名改回去，不然加载出错。

public class Person
{
    public string Name { get; set; }
    public int Age { get; set; }
    public string Sex { get; set; }

    [XmlElement("Dog")]
    public List<Dog> Dog { get; set; }

    public string Good { get; set; } = "100";
    private string valuePrivate { get; set; } = "0";
}

public class Dog
{
    public string Name { get; set; }
    public int Age { get; set; }
}

XmlSerializerHelper

增加了一个，将 XElement节点返序列化成一个对象。这个XmlSerializerHelper序列化返序列化类应该是比较完整了。

class XmlSerializerHelper
{
    public void XmlSerial(object obj, string xmlFile)
    {
        // 序列化
        using (MemoryStream ms = new MemoryStream())
        {
            XmlWriterSettings setting = new XmlWriterSettings() {
                Encoding = new UTF8Encoding(false),
                Indent = true,
            };
            using (XmlWriter writer = XmlWriter.Create(ms, setting))
            {
                XmlSerializer xmlSerializer = new XmlSerializer(obj.GetType());
                // 去掉命名空间
                XmlSerializerNamespaces ns = new XmlSerializerNamespaces();
                ns.Add("", ""); // 命名空间赋值为空
                xmlSerializer.Serialize(writer, obj, ns);

                // 用StreamWriter 
                string xmlContent = Encoding.UTF8.GetString(ms.ToArray()); // 转成字符转
                StreamWriter streamWriter = new StreamWriter(xmlFile);
                streamWriter.Write(xmlContent);
                streamWriter.Close();
            }
        }
    }

    public XElement XmlSerial(object obj)
    {
        // 序列化
        using (MemoryStream ms = new MemoryStream())
        {
            XmlWriterSettings setting = new XmlWriterSettings() {
                Encoding = new UTF8Encoding(false),
                Indent = true,
            };
            using (XmlWriter writer = XmlWriter.Create(ms, setting))
            {
                XmlSerializer xmlSerializer = new XmlSerializer(obj.GetType());
                // 去掉命名空间
                XmlSerializerNamespaces ns = new XmlSerializerNamespaces();
                ns.Add("", ""); // 命名空间赋值为空
                xmlSerializer.Serialize(writer, obj, ns);

                ms.Position = 0;  // 把流的位置弄到最前面，不然找不到根元素

                XDocument objElem = XDocument.Load(ms);
                XElement rootElem = objElem.Root;
                // 可以直接加载
                // XElement rootElem = XElement.Load(ms);
                return rootElem;
            }
        }
    }

    // 返序列化
    public T XmlDeserial<T>(string xmlFile)
    {
        // 用 MemoryStream
        string xmlString = File.ReadAllText(xmlFile); // xml 内容提取出来
        using (MemoryStream MS = new MemoryStream(Encoding.UTF8.GetBytes(xmlString)))
        {
            using (XmlReader xr = XmlReader.Create(MS))
            {
                XmlSerializer xmlSerializer = new XmlSerializer(typeof(T));
                return (T)xmlSerializer.Deserialize(xr);  // 不要误写为 MS 流，有这个重载不会报错。但运行有错。
            }
        }
    }
    // 返序列化
    public T XmlDeserial<T>(XElement xElem)
    {
        xElem.Name = typeof(T).Name; // 如果名称不对，出错。防止改了节点名的情况

        // 用 MemoryStream
        string xmlString = xElem.ToString(); // xml 内容提取出来
        using (MemoryStream MS = new MemoryStream(Encoding.UTF8.GetBytes(xmlString)))
        {
            using (XmlReader xr = XmlReader.Create(MS))
            {
                XmlSerializer xmlSerializer = new XmlSerializer(typeof(T));
                return (T)xmlSerializer.Deserialize(xr);  // 不要误写为 MS 流，有这个重载不会报错。但运行有错。
            }
        }
    }
}

class Program
{
    static void Main(string[] args)
    {
        List<Dog> dogs = new List<Dog> {
            new Dog() { Name = "小黑", Age = 9 },
            new Dog() { Name = "小黄", Age = 10 }
        };

        Person person = new Person() {
            Name = "孙悟空",
            Age = 500,
            Sex = "男",
            Dog = dogs
        };

        XmlSerializerHelper xmlSerializerHelper = new XmlSerializerHelper();
        xmlSerializerHelper.XmlSerial(person, "Person.xml");

        // 返序列化一下
        Person dog_dd = xmlSerializerHelper.XmlDeserial<Person>("Person.xml");
        Console.WriteLine(dog_dd.Name);
        Console.ReadKey();

        // 增加一个 Dog 类
        XElement rootElem = XElement.Load("Person.xml");
        rootElem.Add(xmlSerializerHelper.XmlSerial(new Dog() { Name = "小辉", Age = 15 }));
        rootElem.Save("Person.xml");
        

        /***********下面改下Name属性测试**********/

        XElement rootElement = XElement.Load("Person.xml");
        Dog newDog = new Dog() { Name = "狗蛋", Age = 100 };
        XElement newDogElem = xmlSerializerHelper.XmlSerial(newDog);
        newDogElem.Name = "GouDan";  // 直接改名字
        rootElement.Add(newDogElem);

        XElement gouDan = rootElement.Element("GouDan"); // 根目录加载出来
        rootElement.Save("newPerson.xml");

        Dog dog = xmlSerializerHelper.XmlDeserial<Dog>(gouDan);
        Console.WriteLine("Name = {0}\nAge = {1}", dog.Name, dog.Age);

        Console.ReadKey();
    }
}

输出：

孙悟空
Name = 狗蛋
Age = 100

生成的 XMl 文档：

<?xml version="1.0" encoding="utf-8"?>
<Person>
  <Name>孙悟空</Name>
  <Age>500</Age>
  <Sex>男</Sex>
  <Dog>
    <Name>小黑</Name>
    <Age>9</Age>
  </Dog>
  <Dog>
    <Name>小黄</Name>
    <Age>10</Age>
  </Dog>
  <Good>100</Good>
  <Dog>
    <Name>小辉</Name>
    <Age>15</Age>
  </Dog>
  <GouDan>
    <Name>狗蛋</Name>
    <Age>100</Age>
  </GouDan>
</Person>

可见，上面最后添加的Dog节点改成了GouDan。