SortedDictionary<TKey,TValue>.IDictionary.Keys 屬性

定義

命名空間:

System.Collections.Generic

組件:

System.Collections.dll

來源:

SortedDictionary.cs

取得 ICollection，包含 IDictionary 的索引鍵。

C#

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

屬性值

ICollection

ICollection，包含 IDictionary 的索引鍵。

實作

Keys

範例

下列程式代碼範例示範如何使用 Keys 介面的 System.Collections.IDictionary 屬性搭配 SortedDictionary<TKey,TValue>，以列出字典中的索引鍵。 此範例也會示範如何列舉字典中的索引鍵/值組;請注意，介面的 System.Collections.IDictionary 列舉值會傳 DictionaryEntry 回 物件，而不是 KeyValuePair<TKey,TValue> 物件。

程式代碼範例是較大範例的一部分，包括針對 IDictionary.Add 方法提供的輸出。

C#

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");

C#

// 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);
}

C#

// 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);
}

C#

    }
}

備註

傳回ICollection的索引鍵會根據 Comparer 屬性排序，而且保證順序與 屬性所Values傳回的ICollection對應值相同。

取得此屬性的值是 O (1) 作業。

適用於

另請參閱

• ICollection