XmlElementAttribute.IsNullable Property

The XML schema specification for structures allows an XML document to explicitly signal that an element's content is missing. Such an element contains the attribute xsi:nil set to true. For more information, see the World Wide Web Consortium (www.w3.org) specification, "XML Schema Part 1: Structures".

If the IsNullable property is set to true, the xsi:nil attribute is generated for class members that have been set to null. For example if you set a field named MyStringArray to null, the XmlSerializer generates the following XML code.

 <MyStringArray xsi:nil = "true" />

If the IsNullable property is false, no XML element is generated for class members that have been set to null.

Note
You cannot apply the IsNullable property to a member typed as a value type because a value type cannot contain null. Additionally, you cannot set this property to false for nullable value types. When such types are null, they will be serialized by setting xsi:nil to true.

The following example shows a field with the XmlElementAttribute applied to it, and the IsNullable property set to false.

public class MyClass
{
   [XmlElement(IsNullable = false)]
   public string Group;
}

.NET Framework

.NET Framework Client Profile

Portable Class Library

.NET for Windows Store apps

Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Reference