C#实现XML与实体类之间相互转换的方法(序列化与反序列化)

首先我们需要明确两个概念：序列化和反序列化。序列化是将对象转换为XML或JSON格式的文本数据，而反序列化则是将XML或JSON格式的文本数据转换为对象。

在C#中，我们可以使用XmlSerializer类来实现XML和实体类之间的序列化和反序列化。以下是详细的步骤：

1. 定义实体类

我们先定义一个Person类来说明这个过程：

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

2. 序列化

在代码中创建一个XmlSerializer实例，然后调用Serialize方法将Person对象转换成XML格式的文本：

Person person = new Person()
{
    Name = "John Smith",
    Age = 30,
    Email = "john.smith@example.com"
};

XmlSerializer serializer = new XmlSerializer(typeof(Person));
using (StringWriter writer = new StringWriter())
{
    serializer.Serialize(writer, person);
    string result = writer.ToString();
    Console.WriteLine(result);
}

这段代码将会输出以下XML格式的文本：

<?xml version="1.0" encoding="utf-16"?>
<Person xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <Name>John Smith</Name>
  <Age>30</Age>
  <Email>john.smith@example.com</Email>
</Person>

3. 反序列化

反序列化的过程和序列化相反，我们需要使用XmlSerializer类的Deserialize方法将XML格式的文本转换成Person对象：

string xml = @"<?xml version=""1.0"" encoding=""utf-16""?>
<Person xmlns:xsi=""http://www.w3.org/2001/XMLSchema-instance"" xmlns:xsd=""http://www.w3.org/2001/XMLSchema"">
  <Name>John Smith</Name>
  <Age>30</Age>
  <Email>john.smith@example.com</Email>
</Person>";

XmlSerializer serializer = new XmlSerializer(typeof(Person));
using (StringReader reader = new StringReader(xml))
{
    Person person = (Person)serializer.Deserialize(reader);
    Console.WriteLine(person.Name);
    Console.WriteLine(person.Age);
    Console.WriteLine(person.Email);
}

这段代码将会输出以下结果：

John Smith
30
john.smith@example.com

示例1：序列化和反序列化List对象

上面只是展示了单个对象的序列化和反序列化，实际情况中我们需要序列化的是一个列表，下面给出一个使用List对象的示例。

List<Person> people = new List<Person>()
{
    new Person() { Name = "John", Age = 30, Email = "john@example.com" },
    new Person() { Name = "Jane", Age = 35, Email = "jane@example.com" },
};

XmlSerializer serializer = new XmlSerializer(typeof(List<Person>));
using (StringWriter writer = new StringWriter())
{
    serializer.Serialize(writer, people);
    string result = writer.ToString();
    Console.WriteLine(result);
}

// 反序列化
using (StringReader reader = new StringReader(result))
{
    List<Person> deserializedPeople = (List<Person>)serializer.Deserialize(reader);
    foreach (Person person in deserializedPeople)
    {
        Console.WriteLine(person.Name);
        Console.WriteLine(person.Age);
        Console.WriteLine(person.Email);
    }
}

示例2：自定义XML元素名称

有时候我们需要给XML元素指定特定的名称，而不是使用默认的属性名。这时候我们可以使用XmlAttribute或者XmlText特定来标记实体类属性。

public class PersonWithXmlAttribute
{
    [XmlAttribute("FullName")]
    public string Name { get; set; }
    public int Age { get; set; }
    [XmlText]
    public string Email { get; set; }
}

我们可以使用上面的代码创建一个新的PersonWithXmlAttribute对象并将其序列化：

PersonWithXmlAttribute person = new PersonWithXmlAttribute()
{
    Name = "John Smith",
    Age = 30,
    Email = "john.smith@example.com"
};

XmlSerializer serializer = new XmlSerializer(typeof(PersonWithXmlAttribute));
using (StringWriter writer = new StringWriter())
{
    serializer.Serialize(writer, person);
    string result = writer.ToString();
    Console.WriteLine(result);
}

这段代码将会输出以下XML格式的文本：

<?xml version="1.0" encoding="utf-16"?>
<PersonWithXmlAttribute xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" FullName="John Smith">john.smith@example.com</PersonWithXmlAttribute>

反序列化同样的方法：

string xml = @"<?xml version=""1.0"" encoding=""utf-16""?>
<PersonWithXmlAttribute xmlns:xsi=""http://www.w3.org/2001/XMLSchema-instance"" xmlns:xsd=""http://www.w3.org/2001/XMLSchema"" FullName=""John Smith"">john.smith@example.com</PersonWithXmlAttribute>";

XmlSerializer serializer = new XmlSerializer(typeof(PersonWithXmlAttribute));
using (StringReader reader = new StringReader(xml))
{
    PersonWithXmlAttribute deserializedPerson = (PersonWithXmlAttribute)serializer.Deserialize(reader);
    Console.WriteLine(deserializedPerson.Name);
    Console.WriteLine(deserializedPerson.Age);
    Console.WriteLine(deserializedPerson.Email);
}