XmlAnyAttributeAttribute Class

Definition

Namespace:

System.Xml.Serialization

Assembly:

System.Xml.ReaderWriter.dll

Source:

XmlAnyAttributeAttribute.cs

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

public ref class XmlAnyAttributeAttribute : Attribute

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

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

Public Class XmlAnyAttributeAttribute
Inherits Attribute

Inheritance

Object

Attribute

XmlAnyAttributeAttribute

Attributes

AttributeUsageAttribute

Examples

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="http://www.w3.org/2001/XMLSchema-instance"   
xmlns:xsd="http://www.w3.org/2001/XMLSchema"   
GroupType = 'Technical' GroupNumber = '42' GroupBase = 'Red'>  
  <GroupName>MyGroup</GroupName>  
</Group>  

#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 ref class Group
{
public:
   String^ GroupName;

   // The UnknownAttributes array will be used to collect all unknown
   // attributes found when deserializing.

   [XmlAnyAttributeAttribute]
   array<XmlAttribute^>^XAttributes;
};

void SerializeObject( String^ filename, Object^ g )
{
   XmlSerializer^ ser = gcnew XmlSerializer( Group::typeid );
   TextWriter^ writer = gcnew StreamWriter( filename );
   ser->Serialize( writer, g );
   writer->Close();
}

void DeserializeObject( String^ filename )
{
   XmlSerializer^ ser = gcnew XmlSerializer( Group::typeid );

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

   // Write out the data, including unknown attributes.
   Console::WriteLine( g->GroupName );
   Console::WriteLine(  "Number of unknown attributes: {0}", g->XAttributes->Length );
   for ( IEnumerator ^ e = g->XAttributes->GetEnumerator(); e->MoveNext();  )
   {
      XmlAttribute^ xAtt = safe_cast<XmlAttribute^>(e->Current);
      Console::WriteLine( "{0}: {1}", xAtt->Name, xAtt->InnerXml );
   }
   SerializeObject( "AttributesAdded.xml", g );
}

int main()
{
   // Deserialize the file containing unknown attributes.
   DeserializeObject(  "UnknownAttributes.xml" );
}

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.
   [XmlAnyAttribute]
    public XmlAttribute[]XAttributes;
}

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

      t.DeserializeObject("UnknownAttributes.xml");
   }

   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);
     fs.Close();
     // Write out the data, including unknown attributes.
     Console.WriteLine(g.GroupName);
     Console.WriteLine("Number of unknown attributes: " + 
     g.XAttributes.Length);
     foreach(XmlAttribute xAtt in g.XAttributes){
     Console.WriteLine(xAtt.Name + ": " + xAtt.InnerXml);
     }
     // Serialize the object again with the attributes added.
     this.SerializeObject("AttributesAdded.xml",g);
   }

   private void SerializeObject(string filename, object g){
      XmlSerializer ser = new XmlSerializer(typeof(Group));
      TextWriter writer = new StreamWriter(filename);
      ser.Serialize(writer, g);
      writer.Close();
   }
}

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

Public Class Group
   Public GroupName As String 
   ' The UnknownAttributes array will be used to collect all unknown
   ' attributes found when deserializing.
   <XmlAnyAttribute> _
    Public UnknownAttributes()As XmlAttribute
End Class

Public Class Test
   Shared Sub Main()
      Dim t  As Test = New Test()
      ' Deserialize the file containing unknown attributes.
      t.DeserializeObject("UnknownAttributes.xml")
   End Sub

   Private Sub DeserializeObject(filename As String)
      Dim ser As XmlSerializer = New XmlSerializer(GetType(Group))
      ' A FileStream is needed to read the XML document.
     Dim fs As FileStream = New FileStream(filename, FileMode.Open)
     Dim g As Group = CType(ser.Deserialize(fs), Group)
     fs.Close()
     ' Write out the data, including unknown attributes.
     Console.WriteLine(g.GroupName)
     Console.WriteLine("Number of unknown attributes: " & _ 
     g.UnknownAttributes.Length)
     Dim xAtt As XmlAttribute
     for each xAtt in g.UnknownAttributes
        Console.WriteLine(xAtt.Name & ": " & xAtt.InnerXml)
     Next
     ' Serialize the object again with the attributes added.
     Me.SerializeObject("AttributesAdded.xml",g)
   End Sub

   Private Sub SerializeObject(filename As String, g As object)
      Dim ser As XmlSerializer = New XmlSerializer(GetType(Group))
      DIm writer As TextWriter = New StreamWriter(filename)
      ser.Serialize(writer, g)
      writer.Close()
   End Sub
End Class

Remarks

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.

Note

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

For more information about using attributes, see Attributes.

Constructors

XmlAnyAttributeAttribute()

Constructs a new instance of the XmlAnyAttributeAttribute class.

Properties

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)

See also

• XmlAnyElementAttribute
• XmlSerializer
• XmlAttributes
• Introducing XML Serialization
• How to: Specify an Alternate Element Name for an XML Stream
• Controlling XML Serialization Using Attributes
• Examples of XML Serialization
• XML Schema Definition Tool (Xsd.exe)