SortedDictionary<TKey,TValue>.IDictionary.Keys Proprietà

Definizione

Spazio dei nomi:

System.Collections.Generic

Assembly:

System.Collections.dll

Origine:

SortedDictionary.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 illustra anche come enumerare le coppie chiave/valore nel dizionario; 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 grande, 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 dictionary of strings, with string keys,
        // and access it using the IDictionary interface.
        //
        IDictionary openWith = new SortedDictionary<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.Collections
Imports System.Collections.Generic

Public Class Example
    
    Public Shared Sub Main() 

        ' Create a new sorted dictionary of strings, with string keys,
        ' and access it using the IDictionary interface.
        '
        Dim openWith As IDictionary = _
            New SortedDictionary(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

Commenti

Le chiavi restituite ICollection vengono ordinate in base alla Comparer proprietà e sono garantite nello stesso ordine dei valori corrispondenti nella ICollection proprietà restituita.Values

Ottenere il valore di questa proprietà è un'operazione O(1).

Vedi anche

• ICollection