System.Xml.Serialization.XmlAnyAttributeAttribute Class

Summary

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

C# Syntax:

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

Use the XmlAnyAttributeAttribute to contain arbitrary data (as XML attributes) that might be 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 XmlSerializer.Deserialize method of the XmlSerializer class is called, all attributes that do not have a corresponding member in the class being deserialized will be collected in the array. After deserialization, you can iterate through the collection of XmlAttribute items to process the data.

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

Note In your code, you can use the word XmlAnyAttribute instead of the longer XmlAnyAttributeAttribute.

For more information about using attributes, see the conceptual topic at MSDN: extendingmetadatausingattributes.

The following example collects all unknown attributes into an array of XmlAttribute objects. To try the example, create a file named UnknownAttributes.xml containing 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;
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();
   }
}

    

System.Xml.Serialization Namespace | XmlAnyElementAttribute | XmlSerializer | MSDN: introducingxmlserialization

System.Xml.Serialization.XmlAnyAttributeAttribute Member List:

Public Constructors

ctor #1

Default constructor. This constructor is called by derived class constructors to initialize state in this type. Constructs a new instance of the XmlAnyAttributeAttribute class.

Public Properties

TypeId (inherited from System.Attribute)

Read-only See base class member description: System.Attribute.TypeId When implemented in a derived class, gets a unique identifier for this Attribute.

Public Methods

Equals (inherited from System.Object)	See base class member description: System.Object.Equals Derived from System.Object, the primary base class for all objects.
GetHashCode (inherited from System.Attribute)	See base class member description: System.Attribute.GetHashCode Returns the hash code for this instance.
GetType (inherited from System.Object)	See base class member description: System.Object.GetType Derived from System.Object, the primary base class for all objects.
IsDefaultAttribute (inherited from System.Attribute)	See base class member description: System.Attribute.IsDefaultAttribute When overridden in a derived class, returns an indication whether the value of this instance is the default value for the derived class.
Match (inherited from System.Attribute)	See base class member description: System.Attribute.Match When overridden in a derived class, returns a value indicating whether this instance equals a specified object.
ToString (inherited from System.Object)	See base class member description: System.Object.ToString Derived from System.Object, the primary base class for all objects.

Protected Methods

Finalize (inherited from System.Object)	See base class member description: System.Object.Finalize Derived from System.Object, the primary base class for all objects.
MemberwiseClone (inherited from System.Object)	See base class member description: System.Object.MemberwiseClone Derived from System.Object, the primary base class for all objects.

Hierarchy:

• System.Object
• System.Attribute
• System.Xml.Serialization.XmlAnyAttributeAttribute

System.Xml.Serialization.XmlAnyAttributeAttribute Member Details

Summary

Constructs a new instance of the XmlAnyAttributeAttribute class.

Default constructor. This constructor is called by derived class constructors to initialize state in this type.

C# Syntax:

public XmlAnyAttributeAttribute();

The following example constructs an XmlAnyAttributeAttribute that is used to override the deserialization of an object. To try the example, create a file named UnknownAttributes.xml containing 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;
using System.IO;
using System.Xml.Serialization;
using System.Xml;

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

public class Test{
   static void Main(){
      Test t = new Test();
      t.DeserializeObject("UnknownAttributes.xml");
   }

   private void DeserializeObject(string filename){
      // Use the CreateOverrideSerializer to return an instance
      // of the XmlSerializer customized for overrides.
      XmlSerializer ser = CreateOverrideSerializer();
      // A FileStream is needed to read the XML document.
      FileStream fs = new FileStream(filename, FileMode.Open);
     Group g = (Group)
     	ser.Deserialize(fs);
     fs.Close();
     Console.WriteLine(g.GroupName);
     Console.WriteLine(g.Things.Length);
     foreach(XmlAttribute xAtt in g.Things){
        Console.WriteLine(xAtt.Name + ": " + xAtt.InnerXml);
        }
   }

   private XmlSerializer CreateOverrideSerializer(){
      // Override the Things field to capture all
      // unknown XML attributes.
      XmlAnyAttributeAttribute myAnyAttribute = 
      new XmlAnyAttributeAttribute();
      XmlAttributeOverrides xOverride = 
      new XmlAttributeOverrides();
      XmlAttributes xAtts = new XmlAttributes();
      xAtts.XmlAnyAttribute=myAnyAttribute;
      xOverride.Add(typeof(Group), "Things", xAtts);
       
      return new XmlSerializer(typeof(Group) , xOverride);
   }
}

    

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Inherited
See base class member description: System.Attribute.TypeId

Summary

When implemented in a derived class, gets a unique identifier for this Attribute.

C# Syntax:

public virtual object TypeId {get;}

As implemented, this identifier is merely the Type of the attribute. However, it is intended that the unique identifier be used to identify two attributes of the same type.

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Inherited
See base class member description: System.Object.Equals

C# Syntax:

public virtual bool Equals(    object obj );

For more information on members inherited from System.Object click on the link above.

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Inherited
See base class member description: System.Object.Finalize

C# Syntax:

~XmlAnyAttributeAttribute();

For more information on members inherited from System.Object click on the link above.

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Inherited
See base class member description: System.Attribute.GetHashCode

Summary

Returns the hash code for this instance.

C# Syntax:

public override int GetHashCode();

Return Value:

A 32-bit signed integer hash code.

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Inherited
See base class member description: System.Object.GetType

C# Syntax:

public Type GetType();

For more information on members inherited from System.Object click on the link above.

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Inherited
See base class member description: System.Attribute.IsDefaultAttribute

Summary

When overridden in a derived class, returns an indication whether the value of this instance is the default value for the derived class.

C# Syntax:

public virtual bool IsDefaultAttribute();

Return Value:

true if this instance is the default attribute for the class; otherwise, false.

The default implementation of this class returns false, and must be implemented in the derived class to be useful to that class.

The implementation of this method in a derived class compares the value of this instance to a standard, default value obtained by some means, then returns a Boolean value that indicates whether the value of this instance is equal to the standard. The standard value is typically coded as a constant in the implementation, or stored programmatically in a field used by the implementation.

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Inherited
See base class member description: System.Attribute.Match

Summary

When overridden in a derived class, returns a value indicating whether this instance equals a specified object.

C# Syntax:

public virtual bool Match(    object obj );

obj

An Object to compare with this instance of Attribute.

Return Value:

true if this instance equals obj; otherwise, false.

This method determines if one Attribute equals another. Its default implementation is the same as Attribute.Equals, which performs a value and reference comparison. Override this method to implement support for attribute values, such as flags or bitfields, that consist of components that are meaningful in themselves. For example, consider an attribute whose value is a binary field divided into a bitfield of flags. Two instances of this attribute have one flag in set in common while all the other flags differ. The Equal method cannot determine that the two instances have the same flag set, but the Match method can.

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Inherited
See base class member description: System.Object.MemberwiseClone

C# Syntax:

protected object MemberwiseClone();

For more information on members inherited from System.Object click on the link above.

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Inherited
See base class member description: System.Object.ToString

C# Syntax:

public virtual string ToString();

For more information on members inherited from System.Object click on the link above.

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