How to make a value type nullable with .NET XmlSerializer?

Question

Let\'s suppose I have this object:

[Serializable]
public class MyClass
{
    public int Age { get; set; }
    public int MyClassB { get; set; }
}
[Serializab         


        

Answer 1

Extending Samuel's answer and Greg Beech's comment to the case of a boolean property: if the property is of type bool then you can't write a simple test in the propertySpecified property.

A solution is to use a Nullable type, then the test in the propertySpecified property is simply property.HasValue. e.g.

using System.Xml.Serialization;

public class Person
{
    public bool? Employed { get; set; }

    [XmlIgnore]
    public bool EmployedSpecified { get { return Employed.HasValue; } }
}

An alternative to using a nullable type for a numeric property (suggested by Greg Beech) is to set the value property to an invalid default value, such as -1, as follows:

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

public class Person
{
    [DefaultValue(-1)]
    public int Age { get; set; }

    [XmlIgnore]
    public bool AgeSpecified { get { return Age >= 0; } }
}