XmlAttributeAttribute Class

Definition

Namespace:

System.Xml.Serialization

Assembly:

System.Xml.ReaderWriter.dll

Source:

XmlAttributeAttribute.cs

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

public ref class XmlAttributeAttribute : Attribute

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

[<System.AttributeUsage(System.AttributeTargets.Field | System.AttributeTargets.Parameter | System.AttributeTargets.Property | System.AttributeTargets.ReturnValue)>]
type XmlAttributeAttribute = class
    inherit Attribute

Public Class XmlAttributeAttribute
Inherits Attribute

Inheritance

Object

Attribute

XmlAttributeAttribute

Attributes

AttributeUsageAttribute

Examples

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

#using <System.Xml.dll>
#using <System.dll>

using namespace System;
using namespace System::IO;
using namespace System::Xml;
using namespace System::Xml::Serialization;
using namespace System::Xml::Schema;

public ref class Group
{
public:

   [XmlAttributeAttribute(Namespace="http://www.cpandl.com")]
   String^ GroupName;

   [XmlAttributeAttribute(DataType="base64Binary")]
   array<Byte>^GroupNumber;

   [XmlAttributeAttribute(DataType="date",AttributeName="CreationDate")]
   DateTime Today;
};

void SerializeObject( String^ filename )
{
   // Create an instance of the XmlSerializer class.
   XmlSerializer^ mySerializer = gcnew XmlSerializer( Group::typeid );

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

   // Create an instance of the class that will be serialized.
   Group^ myGroup = gcnew Group;

   // Set the object properties.
   myGroup->GroupName = ".NET";
   array<Byte>^hexByte = {Convert::ToByte( 100 ),Convert::ToByte( 50 )};
   myGroup->GroupNumber = hexByte;
   DateTime myDate = DateTime(2001,1,10);
   myGroup->Today = myDate;

   // Serialize the class, and close the TextWriter.
   mySerializer->Serialize( writer, myGroup );
   writer->Close();
}

int main()
{
   SerializeObject( "Attributes.xml" );
}

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();
      test.SerializeObject("Attributes.xml");
   }

   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),
      Convert.ToByte(50)};
      myGroup.GroupNumber = hexByte;

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

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

Option Explicit
Option Strict

Imports System.IO
Imports System.Xml
Imports System.Xml.Serialization
Imports System.Xml.Schema


Public Class Group
    <XmlAttribute(Namespace := "http://www.cpandl.com")> _
        Public GroupName As String    
    <XmlAttribute(DataType := "base64Binary")> _
        Public GroupNumber() As Byte    
    <XmlAttribute(DataType := "date", AttributeName := "CreationDate")> _
        Public Today As DateTime
End Class

Public Class Run
    
    Public Shared Sub Main()
        Dim test As New Run()
        test.SerializeObject("Attributes.xml")
    End Sub 
    
    Public Sub SerializeObject(ByVal filename As String)
        ' Create an instance of the XmlSerializer class.
        Dim mySerializer As New XmlSerializer(GetType(Group))
        
        ' Writing the file requires a TextWriter.
        Dim writer As New StreamWriter(filename)
        
        ' Create an instance of the class that will be serialized.
        Dim myGroup As New Group()
        
        ' Set the object properties.
        myGroup.GroupName = ".NET"
        
        Dim hexByte() As Byte = {Convert.ToByte(100), Convert.ToByte(50)}
        myGroup.GroupNumber = hexByte
        
        Dim myDate As New DateTime(2001, 1, 10)
        myGroup.Today = myDate
        
        ' Serialize the class, and close the TextWriter.
        mySerializer.Serialize(writer, myGroup)
        writer.Close()
    End Sub
End Class

Remarks

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.

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

<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 Attributes.

Note

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

Constructors

XmlAttributeAttribute()	Initializes a new instance of the XmlAttributeAttribute class.
XmlAttributeAttribute(String, Type)	Initializes a new instance of the XmlAttributeAttribute class.
XmlAttributeAttribute(String)	Initializes a new instance of the XmlAttributeAttribute class and specifies the name of the generated XML attribute.
XmlAttributeAttribute(Type)	Initializes a new instance of the XmlAttributeAttribute class.

Properties

AttributeName	Gets or sets the name of the XML attribute.
DataType	Gets or sets the XSD data type of the XML attribute generated by the XmlSerializer.
Form	Gets or sets a value that indicates whether the XML attribute name generated by the XmlSerializer is qualified.
Namespace	Gets or sets the XML namespace of the XML attribute.
Type	Gets or sets the complex type of the XML attribute.
TypeId	When implemented in a derived class, gets a unique identifier for this Attribute. (Inherited from Attribute)

Methods

Equals(Object)	Returns a value that indicates whether this instance is equal to a specified object. (Inherited from Attribute)
GetHashCode()	Returns the hash code for this instance. (Inherited from Attribute)
GetType()	Gets the Type of the current instance. (Inherited from Object)
IsDefaultAttribute()	When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class. (Inherited from Attribute)
Match(Object)	When overridden in a derived class, returns a value that indicates whether this instance equals a specified object. (Inherited from Attribute)
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
ToString()	Returns a string that represents the current object. (Inherited from Object)