XPathNavigator.InsertElementBefore(String, String, String, String) Method

Definition

Namespace:

System.Xml.XPath

Assembly:

System.Xml.ReaderWriter.dll

Source:

XPathNavigator.cs

Creates a new sibling element before the current node using the namespace prefix, local name, and namespace URI specified, with the value specified.

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

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

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

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

Parameters

prefix

String

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

localName

String

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

namespaceURI

String

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

value

String

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

Exceptions

InvalidOperationException

The position of the XPathNavigator does not allow a new sibling node to be inserted before the current node.

NotSupportedException

The XPathNavigator does not support editing.

Examples

In the following example a new pages element is inserted before the price child element 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->MoveToChild("price", "http://www.contoso.com/books");

navigator->InsertElementBefore(navigator->Prefix, "pages", navigator->LookupNamespace(navigator->Prefix), "100");

navigator->MoveToParent();
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.MoveToChild("price", "http://www.contoso.com/books");

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

navigator.MoveToParent();
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.MoveToChild("price", "http://www.contoso.com/books")

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

navigator.MoveToParent()
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

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

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

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

The following are important notes to consider when using the InsertElementBefore 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 InsertElementBefore method is valid only when the XPathNavigator is positioned on an element, text, processing instruction, or comment node.

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