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IsNullable Property

XmlElementAttribute.IsNullable Property

Gets or sets a value that indicates whether the XmlSerializer must serialize a member that is set to null as an empty tag with the xsi:nil attribute set to true.

Namespace:  System.Xml.Serialization
Assemblies:   System.Xml.XmlSerializer (in System.Xml.XmlSerializer.dll)
  System.Xml (in System.Xml.dll)

public bool IsNullable { get; set; }

Property Value

Type: System.Boolean
true if the XmlSerializer generates the xsi:nil attribute; otherwise, false.

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.

NoteNote

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

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

XNA Framework

Supported in: 3.0, 2.0, 1.0

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone Silverlight 8.1, Windows Phone Silverlight 8

Portable Class Library

Supported in: Portable Class Library
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