如果 object 为空，我如何不序列化 object

Question

Is there a way to not Serialize an object if the object value is null? My xml keeps having a lot of empty

<PersonName></PersonName>

(There is no other object with this value that it's serializing.)

Answer 1

The System.Xml.Serialization.XmlSerializer by default skips null properties. So you don't have to do anything.
Obviously, you need to skip properties equal to string.Empty .

When using XmlSerializer , you can apply the System.ComponentModel.DefaultValue attribute to specify a value that will not be serialized.

For example, you have next class:

public class Person
{        
    public int Id { get; set; }

    [DefaultValue("")]
    public string PersonName { get; set; }

    public int Age { get; set; }
}

When using the following code

var person = new Person { Id = 1, PersonName = "", Age = 20 };

var ser = new XmlSerializer(typeof(Person));
var settings = new XmlWriterSettings { Indent = true };
using (var writer = XmlWriter.Create("result.xml", settings))
{
    ser.Serialize(writer, person);
}

You will get this result

<?xml version="1.0" encoding="utf-8"?>
<Person xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <Id>1</Id>
  <Age>20</Age>
</Person>

But be careful: this attribute is not taken into account during deserialization. Therefore, from such XML you will get a Person class with the PersonName property equal to null .