DictionaryEntry Struct

Definition

public value class DictionaryEntry

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

type DictionaryEntry = struct

Public Structure DictionaryEntry

Inheritance

Object

ValueType

DictionaryEntry

Attributes

ComVisibleAttribute SerializableAttribute

Examples

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

// 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

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:

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

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

Constructors

Properties

Methods

Applies to

See also

• IDictionary
• IDictionaryEnumerator
• KeyValuePair<TKey,TValue>