SortedList<TKey,TValue>.IDictionary.Keys Proprietà

Definizione

Spazio dei nomi:

System.Collections.Generic

Assembly:

System.Collections.dll

Origine:

SortedList.cs

Ottiene ICollection contenente le chiavi di IDictionary.

property System::Collections::ICollection ^ System::Collections::IDictionary::Keys { System::Collections::ICollection ^ get(); };

System.Collections.ICollection System.Collections.IDictionary.Keys { get; }

member this.System.Collections.IDictionary.Keys : System.Collections.ICollection

 ReadOnly Property Keys As ICollection Implements IDictionary.Keys

Valore della proprietà

ICollection

Interfaccia ICollection contenente le chiavi dell'interfaccia IDictionary.

Implementazioni

Keys

Esempio

Nell'esempio di codice seguente viene illustrato come usare la Keys proprietà dell'interfaccia System.Collections.IDictionary con un SortedDictionary<TKey,TValue>oggetto per elencare le chiavi nel dizionario. L'esempio mostra anche come enumerare le coppie chiave/valore nell'elenco ordinato; Si noti che l'enumeratore per l'interfaccia System.Collections.IDictionary restituisce DictionaryEntry oggetti anziché KeyValuePair<TKey,TValue> oggetti .

L'esempio di codice fa parte di un esempio più ampio, incluso l'output, fornito per il IDictionary.Add metodo .

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

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

        // Add some elements to the sorted list. 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.Collections
Imports System.Collections.Generic

Public Class Example
    
    Public Shared Sub Main() 

        ' Create a new sorted list of strings, with string keys,
        ' and access it using the IDictionary interface.
        '
        Dim openWith As IDictionary = _
            New sortedList(Of String, String)
        
        ' Add some elements to the sorted list. 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 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 sorted list 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 sorted list 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 sorted list 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

Commenti

L'ordine delle chiavi in ICollection è uguale all'ordine in SortedList<TKey,TValue>.

Il recupero del valore di questa proprietà è un'operazione O(1).

Vedi anche

• ICollection
• Keys
• Values