XPathNavigator.PrependChild Method

Definition

Namespace:

System.Xml.XPath

Assembly:

System.Xml.ReaderWriter.dll

Creates a new child node at the beginning of the list of child nodes of the current node.

Overloads

PrependChild()	Returns an XmlWriter object used to create a new child node at the beginning of the list of child nodes of the current node.
PrependChild(String)	Creates a new child node at the beginning of the list of child nodes of the current node using the XML string specified.
PrependChild(XmlReader)	Creates a new child node at the beginning of the list of child nodes of the current node using the XML contents of the XmlReader object specified.
PrependChild(XPathNavigator)	Creates a new child node at the beginning of the list of child nodes of the current node using the nodes in the XPathNavigator object specified.

PrependChild()

Source:

XPathNavigator.cs

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

public:
 virtual System::Xml::XmlWriter ^ PrependChild();

public virtual System.Xml.XmlWriter PrependChild ();

abstract member PrependChild : unit -> System.Xml.XmlWriter
override this.PrependChild : unit -> System.Xml.XmlWriter

Public Overridable Function PrependChild () As XmlWriter

Returns

XmlWriter

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

Exceptions

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.

Examples

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 = gcnew 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);

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);

Dim document As XmlDocument = New XmlDocument()
document.Load("contosoBooks.xml")
Dim navigator As XPathNavigator = document.CreateNavigator()

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

Dim pages As XmlWriter = 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>  

Remarks

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.

PrependChild(String)

Source:

XPathNavigator.cs

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

public:
 virtual void PrependChild(System::String ^ newChild);

public virtual void PrependChild (string newChild);

abstract member PrependChild : string -> unit
override this.PrependChild : string -> unit

Public Overridable Sub PrependChild (newChild As String)

Parameters

newChild

String

The XML data string for the new child node.

Exceptions

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.

Examples

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 = gcnew 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);

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);

Dim document As XmlDocument = New XmlDocument()
document.Load("contosoBooks.xml")
Dim navigator As XPathNavigator = 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>  

Remarks

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.

PrependChild(XmlReader)

Source:

XPathNavigator.cs

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

public:
 virtual void PrependChild(System::Xml::XmlReader ^ newChild);

public virtual void PrependChild (System.Xml.XmlReader newChild);

abstract member PrependChild : System.Xml.XmlReader -> unit
override this.PrependChild : System.Xml.XmlReader -> unit

Public Overridable Sub PrependChild (newChild As XmlReader)

Parameters

newChild

XmlReader

An XmlReader object positioned on the XML data for the new child node.

Exceptions

ArgumentException

The XmlReader object is in an error state or closed.

ArgumentNullException

The XmlReader object 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 contents of the XmlReader object parameter is not well-formed.

Examples

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 XmlReader object specified. The http://www.contoso.com/books namespace is specified so that the new child element is prepended using the same namespace as the XML document.

XmlDocument^ document = gcnew 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");

XmlReader^ pages = XmlReader::Create(gcnew StringReader("<pages xmlns=\"http://www.contoso.com/books\">100</pages>"));

navigator->PrependChild(pages);

Console::WriteLine(navigator->OuterXml);

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");

XmlReader pages = XmlReader.Create(new StringReader("<pages xmlns=\"http://www.contoso.com/books\">100</pages>"));

navigator.PrependChild(pages);

Console.WriteLine(navigator.OuterXml);

Dim document As XmlDocument = New XmlDocument()
document.Load("contosoBooks.xml")
Dim navigator As XPathNavigator = document.CreateNavigator()

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

Dim pages As XmlReader = XmlReader.Create(New StringReader("<pages xmlns='http://www.contoso.com/books'>100</pages>"))

navigator.PrependChild(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>  

Remarks

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.

• If the XmlReader object is positioned over a sequence of XML nodes, all the nodes in the sequence are added.

• 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.

PrependChild(XPathNavigator)

Source:

XPathNavigator.cs

Creates a new child node at the beginning of the list of child nodes of the current node using the nodes in the XPathNavigator object specified.

public:
 virtual void PrependChild(System::Xml::XPath::XPathNavigator ^ newChild);

public virtual void PrependChild (System.Xml.XPath.XPathNavigator newChild);

abstract member PrependChild : System.Xml.XPath.XPathNavigator -> unit
override this.PrependChild : System.Xml.XPath.XPathNavigator -> unit

Public Overridable Sub PrependChild (newChild As XPathNavigator)

Parameters

newChild

XPathNavigator

An XPathNavigator object positioned on the node to add as the new child node.

Exceptions

ArgumentNullException

The XPathNavigator object 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.

Examples

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 node contained in the XPathNavigator object specified. The http://www.contoso.com/books namespace is specified so that the new child element is prepended using the same namespace as the XML document.

XmlDocument^ document = gcnew 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");

XmlDocument^ childNodes = gcnew XmlDocument();
childNodes->Load(gcnew StringReader("<pages xmlns=\"http://www.contoso.com/books\">100</pages>"));
XPathNavigator^ childNodesNavigator = childNodes->CreateNavigator();

navigator->PrependChild(childNodesNavigator);

Console::WriteLine(navigator->OuterXml);

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");

XmlDocument childNodes = new XmlDocument();
childNodes.Load(new StringReader("<pages xmlns=\"http://www.contoso.com/books\">100</pages>"));
XPathNavigator childNodesNavigator = childNodes.CreateNavigator();

navigator.PrependChild(childNodesNavigator);

Console.WriteLine(navigator.OuterXml);

Dim document As XmlDocument = New XmlDocument()
document.Load("contosoBooks.xml")
Dim navigator As XPathNavigator = document.CreateNavigator()

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

Dim childNodes As XmlDocument = New XmlDocument()
childNodes.Load(New StringReader("<pages xmlns='http://www.contoso.com/books'>100</pages>"))
Dim childNodesNavigator As XPathNavigator = childNodes.CreateNavigator()

navigator.PrependChild(childNodesNavigator)

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>  

Remarks

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.

• If the XPathNavigator object is positioned over a sequence of XML nodes, all the nodes in the sequence are added.

• 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.