Extensions.Elements<T> Method (IEnumerable<T>, XName)
Returns a filtered collection of the child elements of every element and document in the source collection. Only elements that have a matching XName are included in the collection.
Namespace: System.Xml.Linq
Assembly: System.Xml.Linq (in System.Xml.Linq.dll)
public static IEnumerable<XElement> Elements<T>( this IEnumerable<T> source, XName name ) where T : XContainer
Type Parameters
- T
The type of the objects in source, constrained to XContainer.
Parameters
- source
- Type: System.Collections.Generic.IEnumerable<T>
An IEnumerable<T> of XElement that contains the source collection.
- name
- Type: System.Xml.Linq.XName
The XName to match.
Return Value
Type: System.Collections.Generic.IEnumerable<XElement>An IEnumerable<T> of XElement of the child elements of every element and document in the source collection. Only elements that have a matching XName are included in the collection.
Usage Note
In Visual Basic and C#, you can call this method as an instance method on any object of type IEnumerable<T>. When you use instance method syntax to call this method, omit the first parameter. For more information, see Extension Methods (Visual Basic) or Extension Methods (C# Programming Guide).This extension method is useful when you want to retrieve all elements with a specified name at a particular depth. This is easy if the document is very regular, but if the document is irregular, it can be a bit more difficult. In the following example, we want to retrieve all aaa elements that are children of Item elements. A given Item element may or may not contain an aaa element. This is easily accomplished using this extension method, as follows:
XElement xmlTree = new XElement("Root", new XElement("Item", new XElement("aaa", 1), new XElement("bbb", 2) ), new XElement("Item", new XElement("ccc", 3), new XElement("aaa", 4) ), new XElement("Item", new XElement("ddd", 5), new XElement("eee", 6) ) ); IEnumerable<XElement> allGrandChildren = from el in xmlTree.Elements("Item").Elements("aaa") select el; foreach (XElement el in allGrandChildren) Console.WriteLine(el);
This example produces the following output:
<aaa>1</aaa> <aaa>4</aaa>
The following is the same example, but in this case the XML is in a namespace. For more information, see Working with XML Namespaces.
XNamespace aw = "http://www.adventure-works.com"; XElement xmlTree = new XElement(aw + "Root", new XElement(aw + "Item", new XElement(aw + "aaa", 1), new XElement(aw + "bbb", 2) ), new XElement(aw + "Item", new XElement(aw + "ccc", 3), new XElement(aw + "aaa", 4) ), new XElement(aw + "Item", new XElement(aw + "ddd", 5), new XElement(aw + "eee", 6) ) ); IEnumerable<XElement> allGrandChildren = from el in xmlTree.Elements(aw + "Item").Elements(aw + "aaa") select el; foreach (XElement el in allGrandChildren) Console.WriteLine(el);
This example produces the following output:
<aaa xmlns="http://www.adventure-works.com">1</aaa> <aaa xmlns="http://www.adventure-works.com">4</aaa>
Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
