DictionaryEntry Struct

Definition

public value class DictionaryEntry

public struct DictionaryEntry

[System.Serializable]
public struct DictionaryEntry

[System.Serializable]
[System.Runtime.InteropServices.ComVisible(true)]
public struct DictionaryEntry

type DictionaryEntry = struct

[<System.Serializable>]
type DictionaryEntry = struct

[<System.Serializable>]
[<System.Runtime.InteropServices.ComVisible(true)>]
type DictionaryEntry = struct

Public Structure DictionaryEntry

Inheritance

Object

ValueType

DictionaryEntry

Attributes

SerializableAttribute ComVisibleAttribute

Examples

The following example demonstrates the use of DictionaryEntry to iterate through a Hashtable object.

// 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

Remarks

The IDictionaryEnumerator.Entry method returns an instance of this type.

The C# foreach statement and the Visual Basic For Each statement require the type of each element in the collection. Since each element of the IDictionary is a key/value pair, the element type is not the type of the key or the type of the value. Instead, the element type is DictionaryEntry. For example:

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

The foreach statement is a wrapper around the enumerator, which only allows reading from, not writing to, the collection.

See also

• IDictionary
• IDictionaryEnumerator
• KeyValuePair<TKey,TValue>