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

Определение

Возвращает интерфейс ICollection, содержащий ключи 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

Значение свойства

Коллекция ICollection, содержащая ключи из словаря IDictionary.An ICollection containing the keys of the IDictionary.

Реализации

Примеры

В следующем примере кода показано IDictionary.Keys Dictionary<TKey,TValue>, как использовать свойство System.Collections.IDictionary интерфейса с, чтобы получить список ключей в словаре.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. В примере также показано, как перечислить пары "ключ-значение" в словаре. Обратите внимание, что перечислитель System.Collections.IDictionary для DictionaryEntry интерфейса возвращает объекты KeyValuePair<TKey,TValue> , а не объекты.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.

Пример кода является частью более крупного примера, включая выходные данные, предоставленные для IDictionary.Add метода.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.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

Комментарии

Порядок ключей в возвращаемом ICollection значении не определен, но гарантируется тот же порядок, что и соответствующие значения ICollection в возвращаемом Values свойстве.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.

Получение значения этого свойства является операцией O (1).Getting the value of this property is an O(1) operation.

Применяется к

Дополнительно