XPathNavigator.PrependChild Method ()

 
System_CAPS_noteNote

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Returns an XmlWriter object used to create a new child node at the beginning of the list of child nodes of the current node.

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

public virtual XmlWriter PrependChild()

Return Value

Type: System.Xml.XmlWriter

An XmlWriter object used to create a new child node at the beginning of the list of child nodes of the current node.

Exception Condition
InvalidOperationException

The current node the XPathNavigator is positioned on does not allow a new child node to be prepended.

NotSupportedException

The XPathNavigator does not support editing.

Prepending a child node adds the new node to the beginning of the list of child nodes for the current node. For example, when three child nodes exist for an element, the prepended node becomes the first child node. If no child nodes exist, then a new child node is created.

The following are important notes to consider when using the PrependChild method.

  • The new child node is not inserted until the Close method of the XmlWriter object is called.

  • The PrependChild method is valid only when the XPathNavigator is positioned on an element node.

  • The PrependChild method does not affect the position of the XPathNavigator.

In the following example, a new pages child element is prepended to the beginning of the list of child elements of the first book element in the contosoBooks.xml file using the XmlWriter object returned from the PrependChild method.

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

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

XmlWriter pages = navigator.PrependChild();
pages.WriteElementString("pages", "100");
pages.Close();

Console.WriteLine(navigator.OuterXml);

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
Available since 2.0
Silverlight
Available since 4.0
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