XPathNavigator.AppendChildElement(String, String, String, String) Method

Definition

Namespace:

System.Xml.XPath

Assembly:

System.Xml.ReaderWriter.dll

Source:

XPathNavigator.cs

Creates a new child element node at the end of the list of child nodes of the current node using the namespace prefix, local name and namespace URI specified with the value specified.

public:
 virtual void AppendChildElement(System::String ^ prefix, System::String ^ localName, System::String ^ namespaceURI, System::String ^ value);

public virtual void AppendChildElement (string? prefix, string localName, string? namespaceURI, string? value);

abstract member AppendChildElement : string * string * string * string -> unit
override this.AppendChildElement : string * string * string * string -> unit

Public Overridable Sub AppendChildElement (prefix As String, localName As String, namespaceURI As String, value As String)

Parameters

prefix

String

The namespace prefix of the new child element node (if any).

localName

String

The local name of the new child element node (if any).

namespaceURI

String

The namespace URI of the new child element node (if any). Empty and null are equivalent.

value

String

The value of the new child element node. If Empty or null are passed, an empty element is created.

Exceptions

InvalidOperationException

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

NotSupportedException

The XPathNavigator does not support editing.

Examples

In the following example, a new pages child element is appended to 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->AppendChildElement(navigator->Prefix, "pages", navigator->LookupNamespace(navigator->Prefix), "100");

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.AppendChildElement(navigator.Prefix, "pages", navigator.LookupNamespace(navigator.Prefix), "100");

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.AppendChildElement(navigator.Prefix, "pages", navigator.LookupNamespace(navigator.Prefix), "100")

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

Appending a child node adds the new node to the end of the list of child nodes for the current node. For example, when three child nodes exist for an element node, the appended node becomes the fourth child node. If no child nodes exist, then a new child node is created.

Namespace prefix and URI values can be obtained by using the LookupPrefix method or the LookupNamespace method. For example, the following syntax appends a child element by using the in-scope namespace xmlns:bk=http://www.contoso.com/books:

navigator.AppendChildElement(navigator.Prefix, "pages", LookupNamespaceURI(navigator.Prefix), String.Empty)  

This creates the new child <bk:pages/> element.

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

• If the namespace prefix specified is null or String.Empty, then the prefix for the namespace URI of the new element is obtained from the current namespaces in-scope. If there is no namespace prefix assigned to the specified namespace URI at the current scope, then a namespace prefix is automatically generated.

• The AppendChildElement method is valid only when the XPathNavigator is positioned on the root node or an element node.

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