Dictionary<TKey,TValue>.IDictionary.Keys Dictionary<TKey,TValue>.IDictionary.Keys Dictionary<TKey,TValue>.IDictionary.Keys Property

Definição

Obtém um ICollection que contém as chaves do IDictionary.Gets an ICollection containing the keys of the IDictionary.

property System::Collections::ICollection ^ System::Collections::IDictionary::Keys { System::Collections::ICollection ^ get(); };
System.Collections.ICollection System.Collections.IDictionary.Keys { get; }
 ReadOnly Property Keys As ICollection Implements IDictionary.Keys

Valor da propriedade

Um ICollection que contém as chaves do IDictionary.An ICollection containing the keys of the IDictionary.

Implementações

Exemplos

O exemplo de código a seguir mostra como usar IDictionary.Keys a propriedade System.Collections.IDictionary da interface com um Dictionary<TKey,TValue>, para listar as chaves no dicionário.The following code example shows how to use the IDictionary.Keys property of the System.Collections.IDictionary interface with a Dictionary<TKey,TValue>, to list the keys in the dictionary. O exemplo também mostra como enumerar os pares de chave/valor no dicionário; Observe que o enumerador System.Collections.IDictionary da interface retorna DictionaryEntry objetos em vez de KeyValuePair<TKey,TValue> objetos.The example also shows how to enumerate the key/value pairs in the dictionary; note that the enumerator for the System.Collections.IDictionary interface returns DictionaryEntry objects rather than KeyValuePair<TKey,TValue> objects.

O exemplo de código faz parte de um exemplo maior, inclusive saída, fornecido para o método IDictionary.Add.The code example is part of a larger example, including output, provided for the IDictionary.Add method.

using System;
using System.Collections;
using System.Collections.Generic;

public class Example
{
    public static void Main()
    {
        // Create a new dictionary of strings, with string keys,
        // and access it using the IDictionary interface.
        //
        IDictionary openWith = new Dictionary<string, string>();

        // Add some elements to the dictionary. There are no 
        // duplicate keys, but some of the values are duplicates.
        // IDictionary.Add throws an exception if incorrect types
        // are supplied for key or value.
        openWith.Add("txt", "notepad.exe");
        openWith.Add("bmp", "paint.exe");
        openWith.Add("dib", "paint.exe");
        openWith.Add("rtf", "wordpad.exe");
Imports System
Imports System.Collections
Imports System.Collections.Generic

Public Class Example
    
    Public Shared Sub Main() 

        ' Create a new dictionary of strings, with string keys,
        ' and access it using the IDictionary interface.
        '
        Dim openWith As IDictionary = _
            New Dictionary(Of String, String)
        
        ' Add some elements to the dictionary. There are no 
        ' duplicate keys, but some of the values are duplicates.
        ' IDictionary.Add throws an exception if incorrect types
        ' are supplied for key or value.
        openWith.Add("txt", "notepad.exe")
        openWith.Add("bmp", "paint.exe")
        openWith.Add("dib", "paint.exe")
        openWith.Add("rtf", "wordpad.exe")
// To get the keys alone, use the Keys property.
icoll = openWith.Keys;

// The elements of the collection are strongly typed
// with the type that was specified for dictionary keys,
// even though the ICollection interface is not strongly
// typed.
Console.WriteLine();
foreach( string s in icoll )
{
    Console.WriteLine("Key = {0}", s);
}
' To get the keys alone, use the Keys property.
icoll = openWith.Keys

' The elements of the collection are strongly typed
' with the type that was specified for dictionary keys,
' even though the ICollection interface is not strongly
' typed.
Console.WriteLine()
For Each s As String In  icoll
    Console.WriteLine("Key = {0}", s)
Next s
// When you use foreach to enumerate dictionary elements
// with the IDictionary interface, the elements are retrieved
// as DictionaryEntry objects instead of KeyValuePair objects.
Console.WriteLine();
foreach( DictionaryEntry de in openWith )
{
    Console.WriteLine("Key = {0}, Value = {1}", 
        de.Key, de.Value);
}
' When you use foreach to enumerate dictionary elements
' with the IDictionary interface, the elements are retrieved
' as DictionaryEntry objects instead of KeyValuePair objects.
Console.WriteLine()
For Each de As DictionaryEntry In openWith
    Console.WriteLine("Key = {0}, Value = {1}", _
        de.Key, de.Value)
Next 
    }
}

    End Sub

End Class

Comentários

A ordem das chaves no retornado ICollection não é especificada, mas é garantido que ela seja a mesma ordem que os valores correspondentes ICollection no retornado pela Values propriedade.The order of the keys in the returned ICollection is unspecified, but it is guaranteed to be the same order as the corresponding values in the ICollection returned by the Values property.

A obtenção do valor dessa propriedade é uma operação O(1).Getting the value of this property is an O(1) operation.

Aplica-se a

Veja também