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How to find an element with a specific child element (LINQ to XML)

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This article shows how to find an element whose child element has a specific value.

Example: Find an element whose child element has a specific value

The example finds the Test element whose CommandLine child element has a value of "Examp2.EXE". The example uses XML document Sample XML file: Test configuration.

XElement root = XElement.Load("TestConfig.xml");
IEnumerable<XElement> tests =
    from el in root.Elements("Test")
    where (string)el.Element("CommandLine") == "Examp2.EXE"
    select el;
foreach (XElement el in tests)
    Console.WriteLine((string)el.Attribute("TestId"));

Dim root As XElement = XElement.Load("TestConfig.xml")
Dim tests As IEnumerable(Of XElement) = _
    From el In root.<Test> _
    Where el.<CommandLine>.Value = "Examp2.EXE" _
    Select el
For Each el as XElement In tests
    Console.WriteLine(el.@TestId)
Next

This example produces the following output:

0002
0006

Note that the Visual Basic version of the code uses the XML Child axis property, the XML Attribute axis property, and the XML Value property.

Example: Find when the XML is in a namespace

The following example does the same as the previous one, but for XML that's in a namespace. The example uses XML document Sample XML file: Test configuration in a namespace.

For more information, see Namespaces overview.

XElement root = XElement.Load("TestConfigInNamespace.xml");
XNamespace ad = "http://www.adatum.com";
IEnumerable<XElement> tests =
    from el in root.Elements(ad + "Test")
    where (string)el.Element(ad + "CommandLine") == "Examp2.EXE"
    select el;
foreach (XElement el in tests)
    Console.WriteLine((string)el.Attribute("TestId"));

Imports <xmlns='http://www.adatum.com'>

Module Module1
    Sub Main()
        Dim root As XElement = XElement.Load("TestConfigInNamespace.xml")
        Dim tests As IEnumerable(Of XElement) = _
            From el In root.<Test> _
            Where el.<CommandLine>.Value = "Examp2.EXE" _
            Select el
        For Each el As XElement In tests
            Console.WriteLine(el.@TestId)
        Next
    End Sub
End Module

This example produces the following output:

0002
0006

See also