XPathNavigator.Prefix Property

Definition

Namespace:

System.Xml.XPath

Assembly:

System.Xml.ReaderWriter.dll

Source:

XPathNavigator.cs

When overridden in a derived class, gets the namespace prefix associated with the current node.

public:
 abstract property System::String ^ Prefix { System::String ^ get(); };

public abstract string Prefix { get; }

member this.Prefix : string

Public MustOverride ReadOnly Property Prefix As String

Property Value

String

A String that contains the namespace prefix associated with the current node.

Examples

The following example iterates over the node tree recursively, and displays information about Element and Text nodes.

static void XPathNavigatorMethods_MoveToNext()
{
    
    XPathDocument^ document = gcnew XPathDocument("books.xml");
    XPathNavigator^ navigator = document->CreateNavigator();
    XPathNodeIterator^ nodeset = navigator->Select("descendant::book[author/last-name='Melville']");

    while (nodeset->MoveNext())
    {
        // Clone iterator here when working with it.
        RecursiveWalk(nodeset->Current->Clone());
    }
}

static void RecursiveWalk(XPathNavigator^ navigator)
{
    switch (navigator->NodeType)
    {
    case XPathNodeType::Element:
        if (navigator->Prefix == String::Empty)
                Console::WriteLine("<{0}>", navigator->LocalName);
            else
        Console::Write("<{0}:{1}>", navigator->Prefix, navigator->LocalName);
                Console::WriteLine("\t" + navigator->NamespaceURI);
            break;
    case XPathNodeType::Text:
            Console::WriteLine("\t" + navigator->Value);
            break;
    }

    if (navigator->MoveToFirstChild())
    {
        do
        {
            RecursiveWalk(navigator);
        } while (navigator->MoveToNext());

        navigator->MoveToParent();
        if (navigator->NodeType == XPathNodeType::Element)
            Console::WriteLine("</{0}>", navigator->Name);
    }
    else
    {
        if (navigator->NodeType == XPathNodeType::Element)
        {
            Console::WriteLine("</{0}>", navigator->Name);
       }
    }
}

static void XPathNavigatorMethods_MoveToNext()
{

    XPathDocument document = new XPathDocument("books.xml");
    XPathNavigator navigator = document.CreateNavigator();
    XPathNodeIterator nodeset = navigator.Select("descendant::book[author/last-name='Melville']");

    while (nodeset.MoveNext())
    {
        // Clone iterator here when working with it.
        RecursiveWalk(nodeset.Current.Clone());
    }
}

public static void RecursiveWalk(XPathNavigator navigator)
{
    switch (navigator.NodeType)
    {
        case XPathNodeType.Element:
            if (string.IsNullOrEmpty(navigator.Prefix))
                Console.WriteLine("<{0}>", navigator.LocalName);
            else
                Console.Write("<{0}:{1}>", navigator.Prefix, navigator.LocalName);
            Console.WriteLine("\t" + navigator.NamespaceURI);
            break;
        case XPathNodeType.Text:
            Console.WriteLine("\t" + navigator.Value);
            break;
    }

    if (navigator.MoveToFirstChild())
    {
        do
        {
            RecursiveWalk(navigator);
        } while (navigator.MoveToNext());

        navigator.MoveToParent();
        if (navigator.NodeType == XPathNodeType.Element)
            Console.WriteLine("</{0}>", navigator.Name);
    }
    else
    {
        if (navigator.NodeType == XPathNodeType.Element)
        {
            Console.WriteLine("</{0}>", navigator.Name);
        }
    }
}

Shared Sub XPathNavigatorMethods_MoveToNext()

    Dim document As XPathDocument = New XPathDocument("books.xml")
    Dim navigator As XPathNavigator = document.CreateNavigator()
    Dim nodeset As XPathNodeIterator = navigator.Select("descendant::book[author/last-name='Melville']")

    While nodeset.MoveNext()
        ' Clone iterator here when working with it.
        RecursiveWalk(nodeset.Current.Clone())
    End While

End Sub

Shared Sub RecursiveWalk(ByVal navigator As XPathNavigator)

    Select Case navigator.NodeType
        Case XPathNodeType.Element
            If navigator.Prefix = String.Empty Then
                Console.WriteLine("<{0}>", navigator.LocalName)
            Else
                Console.Write("<{0}:{1}>", navigator.Prefix, navigator.LocalName)
                Console.WriteLine(vbTab + navigator.NamespaceURI)
            End If
        Case XPathNodeType.Text
            Console.WriteLine(vbTab + navigator.Value)
    End Select

    If navigator.MoveToFirstChild() Then
        Do
            RecursiveWalk(navigator)
        Loop While (navigator.MoveToNext())

        navigator.MoveToParent()
        If (navigator.NodeType = XPathNodeType.Element) Then
            Console.WriteLine("</{0}>", navigator.Name)
        End If
    Else
        If navigator.NodeType = XPathNodeType.Element Then
            Console.WriteLine("</{0}>", navigator.Name)
        End If
    End If

End Sub

The example takes the books.xml file as an input.

<?xml version="1.0" encoding="utf-8" ?>   
<bookstore>  
    <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

The Prefix property gets the namespace prefix associated with the current node. For example, the Prefix property returns bk for the <bk:book> element. If a prefix does not exist, or the XPathNodeType of the current node is not Element or Attribute, the Prefix property returns String.Empty.