XAttribute Class
[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]
Represents an XML attribute.
Assembly: System.Xml.Linq (in System.Xml.Linq.dll)
The XAttribute type exposes the following members.
| Name | Description | |
|---|---|---|
 | XAttribute(XAttribute) | Initializes a new instance of the XAttribute class from another XAttribute object. |
| XAttribute(XName, Object) | Initializes a new instance of the XAttribute class from the specified name and value. |
| Name | Description | |
|---|---|---|
 | BaseUri | Gets the base URI for this XObject. (Inherited from XObject.) |
| Document | Gets the XDocument for this XObject. (Inherited from XObject.) |
 | EmptySequence | Gets an empty collection of attributes. |
| IsNamespaceDeclaration | Determines if this attribute is a namespace declaration. |
| Name | Gets the expanded name of this attribute. |
| NextAttribute | Gets the next attribute of the parent element. |
| NodeType | Gets the node type for this node. (Overrides XObject::NodeType.) |
| Parent | Gets the parent XElement of this XObject. (Inherited from XObject.) |
| PreviousAttribute | Gets the previous attribute of the parent element. |
| Value | Gets or sets the value of this attribute. |
| Name | Description | |
|---|---|---|
| AddAnnotation | Adds an object to the annotation list of this XObject. (Inherited from XObject.) |
| Annotation(Type) | Gets the first annotation object of the specified type from this XObject. (Inherited from XObject.) |
| Annotation<T>() | Get the first annotation object of the specified type from this XObject. (Inherited from XObject.) |
| Annotations(Type) | Gets a collection of annotations of the specified type for this XObject. (Inherited from XObject.) |
| Annotations<T>() | Gets a collection of annotations of the specified type for this XObject. (Inherited from XObject.) |
| Equals(Object) | Determines whether the specified Object is equal to the current Object. (Inherited from Object.) |
 | Finalize | Allows an object to try to free resources and perform other cleanup operations before the Object is reclaimed by garbage collection. (Inherited from Object.) |
| GetHashCode | Serves as a hash function for a particular type. (Inherited from Object.) |
| GetType | Gets the Type of the current instance. (Inherited from Object.) |
| MemberwiseClone | Creates a shallow copy of the current Object. (Inherited from Object.) |
| Remove | Removes this attribute from its parent element. |
| RemoveAnnotations(Type) | Removes the annotations of the specified type from this XObject. (Inherited from XObject.) |
| RemoveAnnotations<T>() | Removes the annotations of the specified type from this XObject. (Inherited from XObject.) |
| SetValue | Sets the value of this attribute. |
| ToString | Converts the current XAttribute object to a string representation. (Overrides Object::ToString().) |
| Name | Description | |
|---|---|---|
  | IXmlLineInfo::HasLineInfo | Gets a value indicating whether or not this XObject has line information. (Inherited from XObject.) |
 | IXmlLineInfo::LineNumber | Gets the line number that the underlying XmlReader reported for this XObject. (Inherited from XObject.) |
| IXmlLineInfo::LinePosition | Gets the line position that the underlying XmlReader reported for this XObject. (Inherited from XObject.) |
An XML attribute is a name/value pair associated with an XML element.
Each XElement contains a list of the attributes for that element. Attributes must have a qualified name that is unique to the element. Attributes are not derived from XNode; they are not nodes in the XML tree. Instead, they are simply name/value pairs associated with an element.
Attributes are maintained in the XML tree in the order that they were added to the element. When a collection of attributes is returned by Attributes, they are returned in the order that they were added to the element, and are not sorted.
Technically, in XML, namespace declarations are not attributes proper. However, this distinction is not normally made by many XML programmers. Instead, because namespace declarations have exactly the same XML syntax as attributes, most XML programmers think of namespaces as attributes. To simplify the LINQ to XML programming interface, namespaces are represented in the XML tree as attributes. Such namespace attributes impact serialization of an XML tree. When serializing, LINQ to XML attempts to serialize with the namespace prefix specified in namespace attributes. You can use the IsNamespaceDeclaration to determine if an attribute is really a namespace declaration.
The XAttribute class derives from XObject. You can add annotations to attributes, and observe events for them.
Some XAttribute methods can be used from XAML, for more information, see LINQ to XML Dynamic Properties in the .NET Framework documentation.
The following example uses this constructor to create attributes. It passes strings as the first argument to the XAttribute constructor, which are then implicitly converted to XName objects. The attributes are added to an element.