XPathNavigator.Prefix Eigenschaft

Definition

Namespace:

System.Xml.XPath

Assembly:

System.Xml.ReaderWriter.dll

Quelle:

XPathNavigator.cs

Ruft beim Überschreiben in einer abgeleiteten Klasse das dem aktuellen Knoten zugeordnete Namespacepräfix ab.

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

Eigenschaftswert

String

Eine String, die das dem aktuellen Knoten zugeordnete Namespacepräfix enthält.

Beispiele

Das folgende Beispiel durchläuft die Knotenstruktur rekursiv und zeigt Informationen zu Element knoten und Text an.

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

In diesem Beispiel wird die Datei books.xml als Eingabe verwendet.

<?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>  

Hinweise

Die Prefix -Eigenschaft ruft das Namespacepräfix ab, das dem aktuellen Knoten zugeordnet ist. Beispielsweise gibt die Prefix -Eigenschaft für das <bk:book> -Element zurückbk. Wenn kein Präfix vorhanden ist oder der XPathNodeType des aktuellen Knotens nicht Element oder Attributeist, gibt die Prefix -Eigenschaft zurück String.Empty.