Question

I have a class that I want to serialize

[System.Xml.Serialization.XmlTypeAttribute(Namespace = "http://xyz.com/schema")]
public class Customer
{
    [System.Xml.Serialization.XmlElementAttribute(Order = 0)]
    public int Id { get; set; }

    [System.Xml.Serialization.XmlElementAttribute(Order = 1)]
    public string Name { get; set; }

    [System.Xml.Serialization.XmlElementAttribute(Order = 2)]
    public string Url{ get; set; }

    [System.Xml.Serialization.XmlElementAttribute(Order = 3)]
    public string Count { get; set; }
}

When deserializing if Url is null then the out XML does not contain Url Node.
How can mark it as a required field so that Url node gets created everytime?

Answer 1

The IsNullable attribute should do it.

 [System.Xml.Serialization.XmlElementAttribute(Order = 2,IsNullable=true)]

If its set to true, it should generate the tag (According to MSDN).

If the IsNullable property is set to true, the xsi:nil attribute is
generated for class members that have been set to a null reference
(Nothing in Visual Basic). For example if you set a field named
MyStringArray to a null reference (Nothing in Visual Basic), the
XmlSerializer generates the following XML code.

<MyStringArray xsi:nil = "true" />