DictionaryEntry 結構

定義

命名空間:

System.Collections

組件:

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

下列範例示範 如何使用 DictionaryEntry 來逐一 Hashtable 查看 物件。

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

public ref class Example
{
public:
    static void Main()
    {
        // Create a new hash table.
        //
        Hashtable^ openWith = gcnew 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();
        for each (DictionaryEntry de in openWith)
        {
            Console::WriteLine("Key = {0}, Value = {1}", de.Key, de.Value);
        }
    }
};

int main()
{
    Example::Main();
}

/* 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.
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

方法會 IDictionaryEnumerator.Entry 傳回這個類型的實例。

重要

不建議您將 結構用於 DictionaryEntry 新的開發。 相反地，建議您搭配 類別使用泛型 KeyValuePair<TKey,TValue> 結構 Dictionary<TKey,TValue> 。 如需詳細資訊，請參閱 不應在 GitHub 上使用非泛型集合 。

C# foreach 語句和 Visual Basic For Each 語句需要集合中每個元素的類型。 因為的每個 IDictionary 元素都是索引鍵/值組，所以項目類型不是索引鍵的類型或值的型別。 相反地，元素類型為 DictionaryEntry。 例如：

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

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

語句 foreach 是列舉值周圍的包裝函式，它只允許讀取集合，而不寫入集合。

建構函式

DictionaryEntry(Object, Object)

初始化具有指定索引鍵和值之 DictionaryEntry 型別的執行個體。

屬性

Key	取得或設定索引鍵/值組配對中的索引鍵。
Value	取得或設定索引鍵/值組配對中的值。

方法

Deconstruct(Object, Object)

解構目前的 DictionaryEntry。

另請參閱

• IDictionary
• IDictionaryEnumerator
• KeyValuePair<TKey,TValue>