XPathNavigator.NavigatorComparer Eigenschaft

Definition

Namespace:

System.Xml.XPath

Assembly:

System.Xml.ReaderWriter.dll

Assembly:

System.Xml.XPath.dll

Assembly:

System.Xml.dll

Assembly:

netstandard.dll

Ruft einen IEqualityComparer ab, der für Vergleiche von XPathNavigator-Objekten auf Gleichheit verwendet wird.

public:
 static property System::Collections::IEqualityComparer ^ NavigatorComparer { System::Collections::IEqualityComparer ^ get(); };

public static System.Collections.IEqualityComparer NavigatorComparer { get; }

member this.NavigatorComparer : System.Collections.IEqualityComparer

Public Shared ReadOnly Property NavigatorComparer As IEqualityComparer

Eigenschaftswert

IEqualityComparer

Ein IEqualityComparer, der für Vergleiche von XPathNavigator-Objekten auf Gleichheit verwendet wird.

Beispiele

Im folgenden Beispiel wird die Verwendung der NavigatorComparer Eigenschaft veranschaulicht.

XPathDocument^ document = gcnew XPathDocument("books.xml");
XPathNavigator^ navigator = document->CreateNavigator();
Hashtable^ table = gcnew Hashtable(XPathNavigator::NavigatorComparer);

// Add nodes to the Hashtable.
for each (XPathNavigator^ navigator2 in navigator->Select("//book"))
{
    Object^ value = navigator2->Evaluate("string(./title)");
    table->Add(navigator2->Clone(), value);
    Console::WriteLine("Added book with title {0}", value);
}

Console::WriteLine(table->Count);
Console::WriteLine("Does the Hashtable have the book \"The Confidence Man\"?");
Console::WriteLine(table->Contains(navigator->SelectSingleNode("//book[title='The Confidence Man']")));

XPathDocument document = new XPathDocument("books.xml");
XPathNavigator navigator = document.CreateNavigator();
Hashtable table = new Hashtable(XPathNavigator.NavigatorComparer);

// Add nodes to the Hashtable.
foreach (XPathNavigator navigator2 in navigator.Select("//book"))
{
    object value = navigator2.Evaluate("string(./title)");
    table.Add(navigator2.Clone(), value);
    Console.WriteLine("Added book with title {0}", value);
}

Console.WriteLine(table.Count);
Console.WriteLine("Does the Hashtable have the book \"The Confidence Man\"?");
Console.WriteLine(table.Contains(navigator.SelectSingleNode("//book[title='The Confidence Man']")));

Dim document As XPathDocument = New XPathDocument("books.xml")
Dim navigator As XPathNavigator = document.CreateNavigator()
Dim table As Hashtable = New Hashtable(XPathNavigator.NavigatorComparer)

' Add nodes to the Hashtable.
For Each navigator2 As XPathNavigator In navigator.Select("//book")
    Dim value As Object = navigator2.Evaluate("string(./title)")
    table.Add(navigator2.Clone(), value)
    Console.WriteLine("Added book with title {0}", value)
Next

Console.WriteLine(table.Count)
Console.WriteLine("Does the Hashtable have the book 'The Confidence Man'?")
Console.WriteLine(table.Contains(navigator.SelectSingleNode("//book[title='The Confidence Man']")))

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

Mit der NavigatorComparer Eigenschaft können XPathNavigator Objekte anhand der Position verglichen werden, anstatt auf das Objekt zu verweisen. Equals Die ComparePosition von dieser Klasse implementierten Methoden basieren auf der Position der XPathNavigator als Parameter übergebenen Objekte. Die GetHashCode von dieser Klasse implementierte Methode verwendet die Eigenschaften des Knotens, z. B. den lokalen Namen und den Namespace-URI, um einen Hashcode für den Knoten zu erstellen.