XPathNavigator.SelectAncestors Method (String, String, Boolean)

Selects all the ancestor nodes of the current node that have the specified local name and namespace URI.

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

public virtual XPathNodeIterator SelectAncestors(
	string name,
	string namespaceURI,
	bool matchSelf
)

Parameters

name
Type: System.String

The local name of the ancestor nodes.

namespaceURI
Type: System.String

The namespace URI of the ancestor nodes.

matchSelf
Type: System.Boolean

To include the context node in the selection, true; otherwise, false.

Return Value

Type: System.Xml.XPath.XPathNodeIterator
An XPathNodeIterator that contains the selected nodes. The returned nodes are in reverse document order.

ExceptionCondition
ArgumentNullException

null cannot be passed as a parameter.

If String.Empty is specified as the name parameter, all ancestor nodes that belong to the specified namespace URI are selected. If String.Empty is specified as the namespaceURI parameter, all ancestor nodes with the specified local name that belong to no namespace are selected. If String.Empty is specified as both the local name and namespace URI, all ancestor nodes that belong to no namespace are selected.

The SelectAncestors method has no effect on the state of the XPathNavigator.

The following example illustrates selecting ancestor, child, and descendant nodes.

XPathDocument document = new XPathDocument("contosoBooks.xml");
XPathNavigator navigator = document.CreateNavigator();

navigator.MoveToChild("bookstore", "http://www.contoso.com/books");
navigator.MoveToChild("book", "http://www.contoso.com/books");

// Select all the descendant nodes of the book node.
XPathNodeIterator bookDescendants = navigator.SelectDescendants("", "http://www.contoso.com/books", false);

// Display the LocalName of each descendant node.
Console.WriteLine("Descendant nodes of the book node:");
while (bookDescendants.MoveNext())
{
    Console.WriteLine(bookDescendants.Current.Name);
}

// Select all the child nodes of the book node.
XPathNodeIterator bookChildren = navigator.SelectChildren("", "http://www.contoso.com/books");

// Display the LocalName of each child node.
Console.WriteLine("\nChild nodes of the book node:");
while (bookChildren.MoveNext())
{
    Console.WriteLine(bookChildren.Current.Name);
}

// Select all the ancestor nodes of the title node.
navigator.MoveToChild("title", "http://www.contoso.com/books");

XPathNodeIterator bookAncestors = navigator.SelectAncestors("", "http://www.contoso.com/books", false);

// Display the LocalName of each ancestor node.
Console.WriteLine("\nAncestor nodes of the title node:");

while (bookAncestors.MoveNext())
{
    Console.WriteLine(bookAncestors.Current.Name);
}

The example takes the contosoBooks.xml file as an input.

<?xml version="1.0" encoding="utf-8" ?>
<bookstore xmlns="http://www.contoso.com/books">
    <book genre="autobiography" publicationdate="1981-03-22" ISBN="1-861003-11-0">
        <title>The Autobiography of Benjamin Franklin</title>
        <author>
            <first-name>Benjamin</first-name>
            <last-name>Franklin</last-name>
        </author>
        <price>8.99</price>
    </book>
    <book genre="novel" publicationdate="1967-11-17" ISBN="0-201-63361-2">
        <title>The Confidence Man</title>
        <author>
            <first-name>Herman</first-name>
            <last-name>Melville</last-name>
        </author>
        <price>11.99</price>
    </book>
    <book genre="philosophy" publicationdate="1991-02-15" ISBN="1-861001-57-6">
        <title>The Gorgias</title>
        <author>
            <name>Plato</name>
        </author>
        <price>9.99</price>
    </book>
</bookstore>

.NET Framework

Supported in: 4.6, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, 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.

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