PrependChild Method (String)
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XPathNavigator.PrependChild Method (String)

 

Creates a new child node at the beginning of the list of child nodes of the current node using the XML string specified.

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

public virtual void PrependChild(
	string newChild
)

Parameters

newChild
Type: System.String

The XML data string for the new child node.

Exception Condition
ArgumentNullException

The XML string parameter is null.

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.

XmlException

The XML string parameter is not well-formed.

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.

To create a new element node, include all XML syntax in the XML string parameter. The string for a new book node is PrependChild("<book/>"). The string for appending the text "book" to the current node's text node is PrependChild("book"). If the XML string contains multiple nodes, all nodes are added.

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

  • 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.

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");

navigator.PrependChild("<pages>100</pages>");

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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