Extensions.Elements Method

Definition

Namespace:

System.Xml.Linq

Assemblies:

netstandard.dll, System.Xml.XDocument.dll

Returns a collection of the child elements of every element and document in the source collection.

Overloads

Elements<T>(IEnumerable<T>)	Returns a collection of the child elements of every element and document in the source collection.
Elements<T>(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.

Remarks

Visual Basic contains an integrated elements axis that allows you to find all child elements with a specified XName for every element in the source collection.

This method uses deferred execution.

Elements<T>(IEnumerable<T>)

Source:

Extensions.cs

Returns a collection of the child elements of every element and document in the source collection.

C#

public static System.Collections.Generic.IEnumerable<System.Xml.Linq.XElement> Elements<T>(this System.Collections.Generic.IEnumerable<T?> source) where T : System.Xml.Linq.XContainer;

Type Parameters

T

The type of the objects in source, constrained to XContainer.

Parameters

source

IEnumerable<T>

An IEnumerable<T> of XElement that contains the source collection.

Returns

IEnumerable<XElement>

An IEnumerable<T> of XElement of the child elements of every element or document in the source collection.

Examples

The following example retrieves a collection of elements with the element name of Child. It then uses this axis method to retrieve all child elements of the collection.

C#

XElement xmlTree = new XElement("Root",  
    new XElement("Child",  
        new XElement("GrandChild1", 1),  
        new XElement("GrandChild2", 2)  
    ),  
    new XElement("Child",  
        new XElement("GrandChild3", 3),  
        new XElement("GrandChild4", 4)  
    ),  
    new XElement("Child",  
        new XElement("GrandChild5", 5),  
        new XElement("GrandChild6", 6)  
    )  
);  

IEnumerable<XElement> allGrandChildren =  
    from el in xmlTree.Elements("Child").Elements()  
    select el;  

foreach (XElement el in allGrandChildren)  
    Console.WriteLine(el);  

This example produces the following output:

<GrandChild1>1</GrandChild1>  
<GrandChild2>2</GrandChild2>  
<GrandChild3>3</GrandChild3>  
<GrandChild4>4</GrandChild4>  
<GrandChild5>5</GrandChild5>  
<GrandChild6>6</GrandChild6>  

The following is the same example, but in this case the XML is in a namespace. For more information, see Work with XML Namespaces.

C#

XNamespace aw = "http://www.adventure-works.com";  
XElement xmlTree = new XElement(aw + "Root",  
    new XElement(aw + "Child",  
        new XElement(aw + "GrandChild1", 1),  
        new XElement(aw + "GrandChild2", 2)  
    ),  
    new XElement(aw + "Child",  
        new XElement(aw + "GrandChild3", 3),  
        new XElement(aw + "GrandChild4", 4)  
    ),  
    new XElement(aw + "Child",  
        new XElement(aw + "GrandChild5", 5),  
        new XElement(aw + "GrandChild6", 6)  
    )  
);  

IEnumerable<XElement> allGrandChildren =  
    from el in xmlTree.Elements(aw + "Child").Elements()  
    select el;  

foreach (XElement el in allGrandChildren)  
    Console.WriteLine(el);  

This example produces the following output:

<GrandChild1 xmlns="http://www.adventure-works.com">1</GrandChild1>  
<GrandChild2 xmlns="http://www.adventure-works.com">2</GrandChild2>  
<GrandChild3 xmlns="http://www.adventure-works.com">3</GrandChild3>  
<GrandChild4 xmlns="http://www.adventure-works.com">4</GrandChild4>  
<GrandChild5 xmlns="http://www.adventure-works.com">5</GrandChild5>  
<GrandChild6 xmlns="http://www.adventure-works.com">6</GrandChild6>  

Remarks

Although Visual Basic contains an integrated elements axis that allows you to find all child elements with a specified XName for every element in the source collection, there is no integrated elements axis that allows you to retrieve a collection of every child element for every element in the source collection.

This method uses deferred execution.

See also

• DescendantNodesAndSelf()
• DescendantsAndSelf()
• DescendantNodes()
• Descendants()
• Attributes
• LINQ to XML overview

Elements<T>(IEnumerable<T>, XName)

Source:

Extensions.cs

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.

C#

public static System.Collections.Generic.IEnumerable<System.Xml.Linq.XElement> Elements<T>(this System.Collections.Generic.IEnumerable<T?> source, System.Xml.Linq.XName? name) where T : System.Xml.Linq.XContainer;

Type Parameters

T

The type of the objects in source, constrained to XContainer.

Parameters

source

IEnumerable<T>

An IEnumerable<T> of XElement that contains the source collection.

name

XName

The XName to match.

Returns

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.

Examples

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:

C#

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 Work with XML Namespaces.

C#

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>  

Remarks

Visual Basic users can use the integrated elements axis to retrieve the child elements of every element in a collection.

This method uses deferred execution.

See also

• DescendantNodesAndSelf()
• DescendantsAndSelf()
• DescendantNodes()
• Descendants()
• Attributes
• LINQ to XML overview