XPathNavigator.NavigatorComparer Propriedade

Definição

Namespace:

System.Xml.XPath

Assembly:

System.Xml.ReaderWriter.dll

Assembly:

System.Xml.XPath.dll

Assembly:

System.Xml.dll

Assembly:

netstandard.dll

Obtém um IEqualityComparer usado para a comparação de igualdade de objetos XPathNavigator.

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

Valor da propriedade

IEqualityComparer

Um IEqualityComparer usado para comparação de igualdade de XPathNavigator objetos.

Exemplos

O exemplo a seguir ilustra o uso da NavigatorComparer propriedade.

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']")))

O exemplo usa o arquivo books.xml como entrada.

<?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>  

Comentários

A NavigatorComparer propriedade permite que XPathNavigator os objetos sejam comparados com base na posição em vez de referência ao objeto. Os ComparePosition métodos e Equals os métodos implementados por essa classe baseiam-se na posição dos XPathNavigator objetos passados como parâmetros. O GetHashCode método implementado por essa classe usa as propriedades do nó, como o nome local e o URI do namespace, para criar um código de hash para o nó.