DictionaryEntry 結構

定義

命名空間:

System.Collections

組件:

netstandard.dll, System.Runtime.dll

來源:

DictionaryEntry.cs

定義可設定或擷取的字典索引鍵/值組。

public value class DictionaryEntry

public struct DictionaryEntry

type DictionaryEntry = struct

Public Structure DictionaryEntry

繼承

Object

ValueType

DictionaryEntry

範例

以下範例展示了如何使用 來 DictionaryEntry 遍歷物件 Hashtable 。

// A simple example for the DictionaryEntry structure.
using System;
using System.Collections;

class Example
{
    public static void Main()
    {
        // Create a new hash table.
        //
        Hashtable openWith = new Hashtable();

        // Add some elements to the hash table. There are no
        // duplicate keys, but some of the values are duplicates.
        openWith.Add("txt", "notepad.exe");
        openWith.Add("bmp", "paint.exe");
        openWith.Add("dib", "paint.exe");
        openWith.Add("rtf", "wordpad.exe");

        // When you use foreach to enumerate hash table elements,
        // the elements are retrieved as DictionaryEntry objects.
        Console.WriteLine();
        foreach (DictionaryEntry de in openWith)
        {
            Console.WriteLine("Key = {0}, Value = {1}", de.Key, de.Value);
        }
    }
}

/* This code example produces output similar to the following:

Key = rtf, Value = wordpad.exe
Key = txt, Value = notepad.exe
Key = dib, Value = paint.exe
Key = bmp, Value = paint.exe
 */

'A simple example for the DictionaryEntry structure.
Imports System.Collections

Module Example

    Sub Main()

        ' Create a new hash table.
        '
        Dim openWith As New Hashtable()

        ' Add some elements to the hash table. There are no
        ' duplicate keys, but some of the values are duplicates.
        openWith.Add("txt", "notepad.exe")
        openWith.Add("bmp", "paint.exe")
        openWith.Add("dib", "paint.exe")
        openWith.Add("rtf", "wordpad.exe")

        ' When you use For Each to enumerate hash table elements,
        ' the elements are retrieved as DictionaryEntry objects.
        Console.WriteLine()
        For Each de As DictionaryEntry In openWith
            Console.WriteLine("Key = {0}, Value = {1}", _
                de.Key, de.Value)
        Next de

    End Sub

End Module

' This code example produces output similar to the following:
'
'Key = rtf, Value = wordpad.exe
'Key = txt, Value = notepad.exe
'Key = dib, Value = paint.exe
'Key = bmp, Value = paint.exe

備註

該 IDictionaryEnumerator.Entry 方法回傳此類型的實例。

Important

我們不建議你用這個 DictionaryEntry 結構來進行新開發。 相反地，我們建議你在類別中使用通用 KeyValuePair<TKey,TValue> 結構 Dictionary<TKey,TValue> 。 如需詳細資訊，請參閱 gitHub 上不應 使用非泛型集合 。

C# foreach 陳述式與 Visual Basic For Each 陳述式需要集合中每個元素的型別。 由於 的 IDictionary 每個元素都是鍵值對，因此元素類型既不是鍵的類型，也不是值的類型。 取而代之的是元素類型。DictionaryEntry 例如：

foreach (DictionaryEntry de in openWith)
{
    Console.WriteLine("Key = {0}, Value = {1}", de.Key, de.Value);
}

For Each de As DictionaryEntry In openWith
    Console.WriteLine("Key = {0}, Value = {1}", _
        de.Key, de.Value)
Next de

這個 foreach 陳述句是包裹在列舉器上的封裝器，只允許從集合讀取，不能寫入。

建構函式

名稱	Description
DictionaryEntry(Object, Object)	初始化該類型的實例 DictionaryEntry ，並以指定的鍵值與值。

屬性

名稱	Description
Key	取得或設定鍵值對中的鍵。
Value	取得或設定鍵值對中的值。

方法

名稱	Description
Deconstruct(Object, Object)	解構了當前的 DictionaryEntry。

另請參閱

• IDictionary
• IDictionaryEnumerator
• KeyValuePair<TKey,TValue>