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XmlAnyAttributeAttribute Class

Specifies that the member (a field that returns an array of XmlAttribute objects) can contain any XML attributes.

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

[AttributeUsageAttribute(AttributeTargets.Property|AttributeTargets.Field|AttributeTargets.Parameter|AttributeTargets.ReturnValue, AllowMultiple = false)]
public class XmlAnyAttributeAttribute : Attribute

Use the XmlAnyAttributeAttribute to contain arbitrary data (as XML attributes) that is sent as part of an XML document, such as, metadata sent as part of the document.

Apply the XmlAnyAttributeAttribute to a field that returns an array of XmlAttribute or XmlNode objects. When the Deserialize method of the XmlSerializer class is called, all XML attributes that do not have a corresponding member in the class being deserialized are collected in the array. After deserialization, you can iterate through the collection of XmlAttribute items to process the data.

The UnknownNode and UnknownAttribute events of the XmlSerializer do not occur if you apply the XmlAnyAttributeAttribute to a member of a class.


You can use the word XmlAnyAttribute in your code instead of the longer XmlAnyAttributeAttribute.

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

The following example collects all unknown attributes into an array of XmlAttribute objects. To try the example, create a file named UnknownAttributes.xml that contains the following XML:

 <?xml version="1.0" encoding="utf-8"?>
 <Group xmlns:xsi="" 
 GroupType = 'Technical' GroupNumber = '42' GroupBase = 'Red'>
using System;
using System.IO;
using System.Xml.Serialization;
using System.Xml;

public class Group{
   public string GroupName;
   // The UnknownAttributes array will be used to collect all unknown 
   // attributes found when deserializing.
    public XmlAttribute[]XAttributes;

public class Test{
   static void Main(){
      Test t = new Test();
      // Deserialize the file containing unknown attributes.


   private void DeserializeObject(string filename){
      XmlSerializer ser = new XmlSerializer(typeof(Group));
      // A FileStream is needed to read the XML document.
     FileStream fs = new FileStream(filename, FileMode.Open);
     Group g = (Group) ser.Deserialize(fs);
     // Write out the data, including unknown attributes.
     Console.WriteLine("Number of unknown attributes: " + 
     foreach(XmlAttribute xAtt in g.XAttributes){
     Console.WriteLine(xAtt.Name + ": " + xAtt.InnerXml);
     // Serialize the object again with the attributes added. 

   private void SerializeObject(string filename, object g){
      XmlSerializer ser = new XmlSerializer(typeof(Group));
      TextWriter writer = new StreamWriter(filename);
      ser.Serialize(writer, g);
#using <mscorlib.dll>
#using <System.dll>
#using <System.Xml.dll>

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

public __gc class Group
   String*		GroupName;

   // The UnknownAttributes array will be used to collect all unknown
   // attributes found when deserializing.
   XmlAttribute*	XAttributes[];

void SerializeObject(String* filename, Object* g)
   XmlSerializer* ser = new XmlSerializer(__typeof(Group));
   TextWriter* writer = new StreamWriter(filename);
   ser->Serialize(writer, g);

void DeserializeObject(String* filename)
   XmlSerializer* ser = new XmlSerializer( __typeof( Group ));

   // A FileStream is needed to read the XML document.
   FileStream* fs = new FileStream( filename, FileMode::Open );
   Group* g = __try_cast<Group*>( ser->Deserialize( fs ));

   // Write out the data, including unknown attributes.
   Console::WriteLine("Number of unknown attributes: {0}", __box(g->XAttributes->Length));

   for ( IEnumerator* e = g->XAttributes->GetEnumerator(); e->MoveNext(); )
      XmlAttribute*	xAtt = __try_cast< XmlAttribute* >( e->Current );
      Console::WriteLine( S"{0}: {1}", xAtt->Name, xAtt->InnerXml );
   // Serialize the object again with the attributes added.
   SerializeObject( S"AttributesAdded.xml", g );

int main()
   // Deserialize the file containing unknown attributes.


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

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune

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

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 3.5, 2.0, 1.0

XNA Framework

Supported in: 3.0, 2.0, 1.0