XmlAttributeAttribute Class
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XmlAttributeAttribute Class


Specifies that the XmlSerializer must serialize the class member as an XML attribute.

Namespace:   System.Xml.Serialization
Assembly:  System.Xml (in System.Xml.dll)


[AttributeUsageAttribute(AttributeTargets.Property | AttributeTargets.Field | AttributeTargets.Parameter | AttributeTargets.ReturnValue)]
public class XmlAttributeAttribute : Attribute


Initializes a new instance of the XmlAttributeAttribute class.


Initializes a new instance of the XmlAttributeAttribute class and specifies the name of the generated XML attribute.

System_CAPS_pubmethodXmlAttributeAttribute(String, Type)

Initializes a new instance of the XmlAttributeAttribute class.


Initializes a new instance of the XmlAttributeAttribute class.


Gets or sets the name of the XML attribute.


Gets or sets the XSD data type of the XML attribute generated by the XmlSerializer.


Gets or sets a value that indicates whether the XML attribute name generated by the XmlSerializer is qualified.


Gets or sets the XML namespace of the XML attribute.


Gets or sets the complex type of the XML attribute.


When implemented in a derived class, gets a unique identifier for this Attribute.(Inherited from Attribute.)


This API supports the product infrastructure and is not intended to be used directly from your code. Returns a value that indicates whether this instance is equal to a specified object.(Inherited from Attribute.)


Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object.)


Returns the hash code for this instance.(Inherited from Attribute.)


Gets the Type of the current instance.(Inherited from Object.)


When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class.(Inherited from Attribute.)


When overridden in a derived class, returns a value that indicates whether this instance equals a specified object.(Inherited from Attribute.)


Creates a shallow copy of the current Object.(Inherited from Object.)


Returns a string that represents the current object.(Inherited from Object.)

System_CAPS_pubinterfaceSystem_CAPS_privmethod_Attribute.GetIDsOfNames(Guid, IntPtr, UInt32, UInt32, IntPtr)

Maps a set of names to a corresponding set of dispatch identifiers.(Inherited from Attribute.)

System_CAPS_pubinterfaceSystem_CAPS_privmethod_Attribute.GetTypeInfo(UInt32, UInt32, IntPtr)

Retrieves the type information for an object, which can be used to get the type information for an interface.(Inherited from Attribute.)


Retrieves the number of type information interfaces that an object provides (either 0 or 1).(Inherited from Attribute.)

System_CAPS_pubinterfaceSystem_CAPS_privmethod_Attribute.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr)

Provides access to properties and methods exposed by an object.(Inherited from Attribute.)

The XmlAttributeAttribute belongs to a family of attributes that controls how the XmlSerializer serializes, or deserializes, an object. For a complete list of similar attributes, see Attributes That Control XML Serialization.

When applied to a public field or property, the XmlAttributeAttribute informs the XmlSerializer to serialize the member as an XML attribute. By default, the XmlSerializer serializes public fields and properties as XML elements.

You can assign the XmlAttributeAttribute only to public fields or public properties that return a value (or array of values) that can be mapped to one of the XML Schema definition language (XSD) simple types (including all built-in datatypes derived from the XSD anySimpleType type). The possible types include any that can be mapped to the XSD simple types, including Guid, Char, and enumerations. See the DataType property for a list of XSD types and how they are mapped to.NET data types.

There are two special attributes that can be set with the XmlAttributeAttribute : the xml:lang (specifies language) and xml:space (specifies how to handle white space) attributes. These attributes are intended to convey information that is relevant only to an application processing the XML. Examples of setting these are shown in the following code.

 public string Lang;
 // Set this to 'default' or 'preserve'.
 Namespace = "http://www.w3.org/XML/1998/namespace")]
 public string Space 
 [Visual Basic]
 <XmlAttribute("xml:lang")> _
 Public Lang As String 
 ' Set this to 'default' or 'preserve'.
 <XmlAttribute("space", _
 Namespace:= "http://www.w3.org/XML/1998/namespace")> _
 Public Space As String

For more information about using attributes, see Extending Metadata Using Attributes.


You can use the word XmlAttribute in your code instead of the longer XmlAttributeAttribute.

The following example serializes a class that contains several fields to which the XmlAttributeAttribute is applied.

using System;
using System.IO;
using System.Xml;
using System.Xml.Serialization;
using System.Xml.Schema;

public class Group
   [XmlAttribute (Namespace = "http://www.cpandl.com")]
   public string GroupName;

   [XmlAttribute(DataType = "base64Binary")]
   public Byte [] GroupNumber;

   [XmlAttribute(DataType = "date", AttributeName = "CreationDate")]
   public DateTime Today;

public class Run
   public static void Main()
      Run test = new Run();

   public void SerializeObject(string filename)
      // Create an instance of the XmlSerializer class.
      XmlSerializer mySerializer =  
      new XmlSerializer(typeof(Group));

      // Writing the file requires a TextWriter.
      TextWriter writer = new StreamWriter(filename);

      // Create an instance of the class that will be serialized.
      Group myGroup = new Group();

      // Set the object properties.
      myGroup.GroupName = ".NET";

      Byte [] hexByte = new Byte[2]{Convert.ToByte(100),
      myGroup.GroupNumber = hexByte;

      DateTime myDate = new DateTime(2001,1,10);
      myGroup.Today = myDate;

      // Serialize the class, and close the TextWriter.
      mySerializer.Serialize(writer, myGroup);

Universal Windows Platform
Available since 4.5
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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