Freigeben über

  • Artikel

Extensions.Attributes Method (IEnumerable<XElement>)

Microsoft Silverlight will reach end of support after October 2021. Learn more.

Returns a collection of the attributes of every element in the source collection.

Namespace:  System.Xml.Linq
Assembly:  System.Xml.Linq (in System.Xml.Linq.dll)

Syntax

'Declaration
<ExtensionAttribute> _
Public Shared Function Attributes ( _
    source As IEnumerable(Of XElement) _
) As IEnumerable(Of XAttribute)

public static IEnumerable<XAttribute> Attributes(
    this IEnumerable<XElement> source
)

Parameters

Return Value

Type: System.Collections.Generic.IEnumerable<XAttribute>
An IEnumerable<T> of XAttribute that contains the attributes of every element in the source collection.

Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type IEnumerable<XElement>. When you use instance method syntax to call this method, omit the first parameter.

Exceptions

Exception Condition
ArgumentNullException

source is nulla null reference (Nothing in Visual Basic).

Remarks

Note that unlike some other XML programming interfaces, in LINQ to XML, namespaces are surfaced as attributes.

Although Visual Basic users can use the integrated attribute axis to retrieve attributes with a specified name from a collection of elements, there is no integrated Visual Basic axis to retrieve all attributes of all elements in a collection.

This method uses deferred execution.

Examples

The following example retrieves a collection of elements, and then retrieves a collection of all attributes of all elements in the collection. Note that the resulting collection includes only the attributes of the Child1 and Child2 elements, and not the attributes of the Root element.

Note that the namespace attribute is returned by this method.

Dim output As New StringBuilder
Dim xmlTree As XElement = _
    <Root xmlns:aw="https://www.adventure-works.com" Att1="content1" Att2="content2">
        <Child1 Att1="content3" Att2="content4"/>
        <Child2 Att1="content5" Att2="content6"/>
    </Root>

Dim attList = _
    From att In xmlTree.DescendantsAndSelf.Attributes _
    Select att

output.Append(xmlTree)
output.Append(Environment.NewLine)
output.Append("-----")
output.Append(Environment.NewLine)

For Each att As XAttribute In attList
    output.Append(att)
    output.Append(Environment.NewLine)
Next

OutputTextBlock.Text = output.ToString()

StringBuilder output = new StringBuilder();
XElement xmlTree = new XElement("Root",
    new XAttribute(XNamespace.Xmlns + "aw", "https://www.adventure-works.com"),
    new XAttribute("Att1", "content1"),
    new XAttribute("Att2", "content2"),
    new XElement("Child1",
        new XAttribute("Att1", "content3"),
        new XAttribute("Att2", "content4")
    ),
    new XElement("Child2",
        new XAttribute("Att1", "content5"),
        new XAttribute("Att2", "content6")
    )
);
output.Append(xmlTree + Environment.NewLine);
output.Append("-----" + Environment.NewLine);

IEnumerable<XAttribute> attList =
    from att in xmlTree.DescendantsAndSelf().Attributes()
    select att;

foreach (XAttribute att in attList)
    output.Append(att + Environment.NewLine);

OutputTextBlock.Text = output.ToString();

Version Information

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Xbox 360, Windows Phone OS 7.0

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.