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XPathNavigator.ReadSubtree Method

Note: This method is new in the .NET Framework version 2.0.

Returns an XmlReader object that contains the current node and its child nodes.

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

public virtual XmlReader ReadSubtree ()
public XmlReader ReadSubtree ()
public function ReadSubtree () : XmlReader

Return Value

An XmlReader object that contains the current node and its child nodes.

Exception typeCondition


The XPathNavigator is not positioned on an element node or the root node.

When the XmlReader object is created with the current node and its child nodes, the XmlReader object's ReadState property is set to Initial. When the XmlReader object's Read method is called for the first time, the XmlReader is moved to the current node of the XPathNavigator. The new XmlReader object continues to read until the end of the XML tree is reached. At this point, the Read method returns false and the XmlReader object's ReadState property is set to EndOfFile.


Changing the position of the XmlReader object does not affect the position of the XPathNavigator.

Namespace declarations for the in-scope namespaces of the current node are not inserted into the XML stream provided to the XmlReader object.


This behavior differs from the WriteSubtree method.

The following example illustrates using the ReadSubtree method on the first book element of the contosoBooks.xml file.

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");

XmlReader reader = navigator.ReadSubtree();

while (reader.Read())


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

<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>
    <book genre="novel" publicationdate="1967-11-17" ISBN="0-201-63361-2">
        <title>The Confidence Man</title>
    <book genre="philosophy" publicationdate="1991-02-15" ISBN="1-861001-57-6">
        <title>The Gorgias</title>

Windows 98, Windows 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0

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