HybridDictionary.GetEnumerator Méthode

Définition

Retourne un IDictionaryEnumerator qui itère au sein de HybridDictionary.Returns an IDictionaryEnumerator that iterates through the HybridDictionary.

public:
 virtual System::Collections::IDictionaryEnumerator ^ GetEnumerator();
public System.Collections.IDictionaryEnumerator GetEnumerator ();
abstract member GetEnumerator : unit -> System.Collections.IDictionaryEnumerator
override this.GetEnumerator : unit -> System.Collections.IDictionaryEnumerator
Public Function GetEnumerator () As IDictionaryEnumerator

Retours

IDictionaryEnumerator

IDictionaryEnumerator pour HybridDictionary.An IDictionaryEnumerator for the HybridDictionary.

Implémente

Exemples

L’exemple de code suivant énumère les éléments d’un HybridDictionary .The following code example enumerates the elements of a HybridDictionary.

#using <System.dll>

using namespace System;
using namespace System::Collections;
using namespace System::Collections::Specialized;

void PrintKeysAndValues1( IDictionary^ myCol );
void PrintKeysAndValues2( IDictionary^ myCol );
void PrintKeysAndValues3( HybridDictionary^ myCol );

int main()
{
   // Creates and initializes a new HybridDictionary.
   HybridDictionary^ myCol = gcnew HybridDictionary;
   myCol->Add( "Braeburn Apples", "1.49" );
   myCol->Add( "Fuji Apples", "1.29" );
   myCol->Add( "Gala Apples", "1.49" );
   myCol->Add( "Golden Delicious Apples", "1.29" );
   myCol->Add( "Granny Smith Apples", "0.89" );
   myCol->Add( "Red Delicious Apples", "0.99" );
   myCol->Add( "Plantain Bananas", "1.49" );
   myCol->Add( "Yellow Bananas", "0.79" );
   myCol->Add( "Strawberries", "3.33" );
   myCol->Add( "Cranberries", "5.98" );
   myCol->Add( "Navel Oranges", "1.29" );
   myCol->Add( "Grapes", "1.99" );
   myCol->Add( "Honeydew Melon", "0.59" );
   myCol->Add( "Seedless Watermelon", "0.49" );
   myCol->Add( "Pineapple", "1.49" );
   myCol->Add( "Nectarine", "1.99" );
   myCol->Add( "Plums", "1.69" );
   myCol->Add( "Peaches", "1.99" );

   // Display the contents of the collection using for each. This is the preferred method.
   Console::WriteLine( "Displays the elements using for each:" );
   PrintKeysAndValues1( myCol );

   // Display the contents of the collection using the enumerator.
   Console::WriteLine( "Displays the elements using the IDictionaryEnumerator:" );
   PrintKeysAndValues2( myCol );

   // Display the contents of the collection using the Keys, Values, Count, and Item properties.
   Console::WriteLine( "Displays the elements using the Keys, Values, Count, and Item properties:" );
   PrintKeysAndValues3( myCol );
}

// Uses the foreach statement which hides the complexity of the enumerator.
// NOTE: The foreach statement is the preferred way of enumerating the contents of a collection.
void PrintKeysAndValues1( IDictionary^ myCol )  {
   Console::WriteLine( "   KEY                       VALUE" );
   for each ( DictionaryEntry^ de in myCol )
      Console::WriteLine( "   {0,-25} {1}", de->Key, de->Value );
   Console::WriteLine();
}

// Uses the enumerator. 
void PrintKeysAndValues2( IDictionary^ myCol )
{
   IDictionaryEnumerator^ myEnumerator = myCol->GetEnumerator();
   Console::WriteLine( "   KEY                       VALUE" );
   while ( myEnumerator->MoveNext() )
      Console::WriteLine( "   {0,-25} {1}", myEnumerator->Key, myEnumerator->Value );

   Console::WriteLine();
}

// Uses the Keys, Values, Count, and Item properties.
void PrintKeysAndValues3( HybridDictionary^ myCol )
{
   array<String^>^myKeys = gcnew array<String^>(myCol->Count);
   myCol->Keys->CopyTo( myKeys, 0 );
   Console::WriteLine( "   INDEX KEY                       VALUE" );
   for ( int i = 0; i < myCol->Count; i++ )
      Console::WriteLine( "   {0,-5} {1,-25} {2}", i, myKeys[ i ], myCol[ myKeys[ i ] ] );
   Console::WriteLine();
}

/*
This code produces output similar to the following:

Displays the elements using for each:
   KEY                       VALUE
   Seedless Watermelon       0.49
   Nectarine                 1.99
   Cranberries               5.98
   Plantain Bananas          1.49
   Honeydew Melon            0.59
   Pineapple                 1.49
   Strawberries              3.33
   Grapes                    1.99
   Braeburn Apples           1.49
   Peaches                   1.99
   Red Delicious Apples      0.99
   Golden Delicious Apples   1.29
   Yellow Bananas            0.79
   Granny Smith Apples       0.89
   Gala Apples               1.49
   Plums                     1.69
   Navel Oranges             1.29
   Fuji Apples               1.29

Displays the elements using the IDictionaryEnumerator:
   KEY                       VALUE
   Seedless Watermelon       0.49
   Nectarine                 1.99
   Cranberries               5.98
   Plantain Bananas          1.49
   Honeydew Melon            0.59
   Pineapple                 1.49
   Strawberries              3.33
   Grapes                    1.99
   Braeburn Apples           1.49
   Peaches                   1.99
   Red Delicious Apples      0.99
   Golden Delicious Apples   1.29
   Yellow Bananas            0.79
   Granny Smith Apples       0.89
   Gala Apples               1.49
   Plums                     1.69
   Navel Oranges             1.29
   Fuji Apples               1.29

Displays the elements using the Keys, Values, Count, and Item properties:
   INDEX KEY                       VALUE
   0     Seedless Watermelon       0.49
   1     Nectarine                 1.99
   2     Cranberries               5.98
   3     Plantain Bananas          1.49
   4     Honeydew Melon            0.59
   5     Pineapple                 1.49
   6     Strawberries              3.33
   7     Grapes                    1.99
   8     Braeburn Apples           1.49
   9     Peaches                   1.99
   10    Red Delicious Apples      0.99
   11    Golden Delicious Apples   1.29
   12    Yellow Bananas            0.79
   13    Granny Smith Apples       0.89
   14    Gala Apples               1.49
   15    Plums                     1.69
   16    Navel Oranges             1.29
   17    Fuji Apples               1.29

*/
using System;
using System.Collections;
using System.Collections.Specialized;

public class SamplesHybridDictionary  {

   public static void Main()  {

      // Creates and initializes a new HybridDictionary.
      HybridDictionary myCol = new HybridDictionary();
      myCol.Add( "Braeburn Apples", "1.49" );
      myCol.Add( "Fuji Apples", "1.29" );
      myCol.Add( "Gala Apples", "1.49" );
      myCol.Add( "Golden Delicious Apples", "1.29" );
      myCol.Add( "Granny Smith Apples", "0.89" );
      myCol.Add( "Red Delicious Apples", "0.99" );
      myCol.Add( "Plantain Bananas", "1.49" );
      myCol.Add( "Yellow Bananas", "0.79" );
      myCol.Add( "Strawberries", "3.33" );
      myCol.Add( "Cranberries", "5.98" );
      myCol.Add( "Navel Oranges", "1.29" );
      myCol.Add( "Grapes", "1.99" );
      myCol.Add( "Honeydew Melon", "0.59" );
      myCol.Add( "Seedless Watermelon", "0.49" );
      myCol.Add( "Pineapple", "1.49" );
      myCol.Add( "Nectarine", "1.99" );
      myCol.Add( "Plums", "1.69" );
      myCol.Add( "Peaches", "1.99" );

      // Display the contents of the collection using foreach. This is the preferred method.
      Console.WriteLine( "Displays the elements using foreach:" );
      PrintKeysAndValues1( myCol );

      // Display the contents of the collection using the enumerator.
      Console.WriteLine( "Displays the elements using the IDictionaryEnumerator:" );
      PrintKeysAndValues2( myCol );

      // Display the contents of the collection using the Keys, Values, Count, and Item properties.
      Console.WriteLine( "Displays the elements using the Keys, Values, Count, and Item properties:" );
      PrintKeysAndValues3( myCol );
   }

   // Uses the foreach statement which hides the complexity of the enumerator.
   // NOTE: The foreach statement is the preferred way of enumerating the contents of a collection.
   public static void PrintKeysAndValues1( IDictionary myCol )  {
      Console.WriteLine( "   KEY                       VALUE" );
      foreach ( DictionaryEntry de in myCol )
         Console.WriteLine( "   {0,-25} {1}", de.Key, de.Value );
      Console.WriteLine();
   }

   // Uses the enumerator.
   // NOTE: The foreach statement is the preferred way of enumerating the contents of a collection.
   public static void PrintKeysAndValues2( IDictionary myCol )  {
      IDictionaryEnumerator myEnumerator = myCol.GetEnumerator();
      Console.WriteLine( "   KEY                       VALUE" );
      while ( myEnumerator.MoveNext() )
         Console.WriteLine( "   {0,-25} {1}", myEnumerator.Key, myEnumerator.Value );
      Console.WriteLine();
   }

   // Uses the Keys, Values, Count, and Item properties.
   public static void PrintKeysAndValues3( HybridDictionary myCol )  {
      String[] myKeys = new String[myCol.Count];
      myCol.Keys.CopyTo( myKeys, 0 );

      Console.WriteLine( "   INDEX KEY                       VALUE" );
      for ( int i = 0; i < myCol.Count; i++ )
         Console.WriteLine( "   {0,-5} {1,-25} {2}", i, myKeys[i], myCol[myKeys[i]] );
      Console.WriteLine();
   }
}

/*
This code produces output similar to the following:

Displays the elements using foreach:
   KEY                       VALUE
   Seedless Watermelon       0.49
   Nectarine                 1.99
   Cranberries               5.98
   Plantain Bananas          1.49
   Honeydew Melon            0.59
   Pineapple                 1.49
   Strawberries              3.33
   Grapes                    1.99
   Braeburn Apples           1.49
   Peaches                   1.99
   Red Delicious Apples      0.99
   Golden Delicious Apples   1.29
   Yellow Bananas            0.79
   Granny Smith Apples       0.89
   Gala Apples               1.49
   Plums                     1.69
   Navel Oranges             1.29
   Fuji Apples               1.29

Displays the elements using the IDictionaryEnumerator:
   KEY                       VALUE
   Seedless Watermelon       0.49
   Nectarine                 1.99
   Cranberries               5.98
   Plantain Bananas          1.49
   Honeydew Melon            0.59
   Pineapple                 1.49
   Strawberries              3.33
   Grapes                    1.99
   Braeburn Apples           1.49
   Peaches                   1.99
   Red Delicious Apples      0.99
   Golden Delicious Apples   1.29
   Yellow Bananas            0.79
   Granny Smith Apples       0.89
   Gala Apples               1.49
   Plums                     1.69
   Navel Oranges             1.29
   Fuji Apples               1.29

Displays the elements using the Keys, Values, Count, and Item properties:
   INDEX KEY                       VALUE
   0     Seedless Watermelon       0.49
   1     Nectarine                 1.99
   2     Cranberries               5.98
   3     Plantain Bananas          1.49
   4     Honeydew Melon            0.59
   5     Pineapple                 1.49
   6     Strawberries              3.33
   7     Grapes                    1.99
   8     Braeburn Apples           1.49
   9     Peaches                   1.99
   10    Red Delicious Apples      0.99
   11    Golden Delicious Apples   1.29
   12    Yellow Bananas            0.79
   13    Granny Smith Apples       0.89
   14    Gala Apples               1.49
   15    Plums                     1.69
   16    Navel Oranges             1.29
   17    Fuji Apples               1.29

*/
Imports System.Collections
Imports System.Collections.Specialized

Public Class SamplesHybridDictionary   

   Public Shared Sub Main()

      ' Creates and initializes a new HybridDictionary.
      Dim myCol As New HybridDictionary()
      myCol.Add("Braeburn Apples", "1.49")
      myCol.Add("Fuji Apples", "1.29")
      myCol.Add("Gala Apples", "1.49")
      myCol.Add("Golden Delicious Apples", "1.29")
      myCol.Add("Granny Smith Apples", "0.89")
      myCol.Add("Red Delicious Apples", "0.99")
      myCol.Add("Plantain Bananas", "1.49")
      myCol.Add("Yellow Bananas", "0.79")
      myCol.Add("Strawberries", "3.33")
      myCol.Add("Cranberries", "5.98")
      myCol.Add("Navel Oranges", "1.29")
      myCol.Add("Grapes", "1.99")
      myCol.Add("Honeydew Melon", "0.59")
      myCol.Add("Seedless Watermelon", "0.49")
      myCol.Add("Pineapple", "1.49")
      myCol.Add("Nectarine", "1.99")
      myCol.Add("Plums", "1.69")
      myCol.Add("Peaches", "1.99")

      ' Display the contents of the collection using For Each. This is the preferred method.
      Console.WriteLine("Displays the elements using For Each:")
      PrintKeysAndValues1(myCol)

      ' Display the contents of the collection using the enumerator.
      Console.WriteLine("Displays the elements using the IDictionaryEnumerator:")
      PrintKeysAndValues2(myCol)

      ' Display the contents of the collection using the Keys, Values, Count, and Item properties.
      Console.WriteLine("Displays the elements using the Keys, Values, Count, and Item properties:")
      PrintKeysAndValues3(myCol)

   End Sub


   ' Uses the For Each statement which hides the complexity of the enumerator.
   ' NOTE: The For Each statement is the preferred way of enumerating the contents of a collection.
   Public Shared Sub PrintKeysAndValues1(myCol As IDictionary)

      Console.WriteLine("   KEY                       VALUE")
      Dim de As DictionaryEntry
      For Each de In  myCol
         Console.WriteLine("   {0,-25} {1}", de.Key, de.Value)
      Next de
      Console.WriteLine()

   End Sub


   ' Uses the enumerator. 
   ' NOTE: The For Each statement is the preferred way of enumerating the contents of a collection.
   Public Shared Sub PrintKeysAndValues2(myCol As IDictionary)
      Dim myEnumerator As IDictionaryEnumerator = myCol.GetEnumerator()

      Console.WriteLine("   KEY                       VALUE")
      While myEnumerator.MoveNext()
         Console.WriteLine("   {0,-25} {1}", myEnumerator.Key, myEnumerator.Value)
      End While
      Console.WriteLine()

   End Sub


   ' Uses the Keys, Values, Count, and Item properties.
   Public Shared Sub PrintKeysAndValues3(myCol As HybridDictionary)
      Dim myKeys(myCol.Count) As [String]
      myCol.Keys.CopyTo(myKeys, 0)

      Console.WriteLine("   INDEX KEY                       VALUE")
      Dim i As Integer
      For i = 0 To myCol.Count - 1
         Console.WriteLine("   {0,-5} {1,-25} {2}", i, myKeys(i), myCol(myKeys(i)))
      Next i
      Console.WriteLine()

   End Sub

End Class


'This code produces output similar to the following:
'
'Displays the elements using For Each:
'   KEY                       VALUE
'   Seedless Watermelon       0.49
'   Nectarine                 1.99
'   Cranberries               5.98
'   Plantain Bananas          1.49
'   Honeydew Melon            0.59
'   Pineapple                 1.49
'   Strawberries              3.33
'   Grapes                    1.99
'   Braeburn Apples           1.49
'   Peaches                   1.99
'   Red Delicious Apples      0.99
'   Golden Delicious Apples   1.29
'   Yellow Bananas            0.79
'   Granny Smith Apples       0.89
'   Gala Apples               1.49
'   Plums                     1.69
'   Navel Oranges             1.29
'   Fuji Apples               1.29
'
'Displays the elements using the IDictionaryEnumerator:
'   KEY                       VALUE
'   Seedless Watermelon       0.49
'   Nectarine                 1.99
'   Cranberries               5.98
'   Plantain Bananas          1.49
'   Honeydew Melon            0.59
'   Pineapple                 1.49
'   Strawberries              3.33
'   Grapes                    1.99
'   Braeburn Apples           1.49
'   Peaches                   1.99
'   Red Delicious Apples      0.99
'   Golden Delicious Apples   1.29
'   Yellow Bananas            0.79
'   Granny Smith Apples       0.89
'   Gala Apples               1.49
'   Plums                     1.69
'   Navel Oranges             1.29
'   Fuji Apples               1.29
'
'Displays the elements using the Keys, Values, Count, and Item properties:
'   INDEX KEY                       VALUE
'   0     Seedless Watermelon       0.49
'   1     Nectarine                 1.99
'   2     Cranberries               5.98
'   3     Plantain Bananas          1.49
'   4     Honeydew Melon            0.59
'   5     Pineapple                 1.49
'   6     Strawberries              3.33
'   7     Grapes                    1.99
'   8     Braeburn Apples           1.49
'   9     Peaches                   1.99
'   10    Red Delicious Apples      0.99
'   11    Golden Delicious Apples   1.29
'   12    Yellow Bananas            0.79
'   13    Granny Smith Apples       0.89
'   14    Gala Apples               1.49
'   15    Plums                     1.69
'   16    Navel Oranges             1.29
'   17    Fuji Apples               1.29

Remarques

L'instruction foreach du langage C# (for each en Visual Basic) se charge de la complexité des énumérateurs.The foreach statement of the C# language (for each in Visual Basic) hides the complexity of the enumerators. Il est donc recommandé d'utiliser foreach plutôt que de manipuler l'énumérateur directement.Therefore, using foreach is recommended, instead of directly manipulating the enumerator.

Les énumérateurs peuvent être utilisés pour lire les données de la collection, mais ils ne permettent pas de modifier la collection sous-jacente.Enumerators can be used to read the data in the collection, but they cannot be used to modify the underlying collection.

Au départ, l'énumérateur est positionné avant le premier élément de la collection.Initially, the enumerator is positioned before the first element in the collection. Reset replace également l'énumérateur à cette position.Reset also brings the enumerator back to this position. À cette position, Current n'est pas défini.At this position, Current is undefined. Par conséquent, vous devez appeler MoveNext pour avancer l'énumérateur jusqu'au premier élément de la collection avant de lire la valeur de Current.Therefore, you must call MoveNext to advance the enumerator to the first element of the collection before reading the value of Current.

Current retourne le même objet tant que MoveNext ou Reset n'est pas appelé.Current returns the same object until either MoveNext or Reset is called. MoveNext affecte l'élément suivant à Current.MoveNext sets Current to the next element.

Si MoveNext passe la fin de la collection, l’énumérateur est positionné après le dernier élément de la collection et MoveNext retourne false .If MoveNext passes the end of the collection, the enumerator is positioned after the last element in the collection and MoveNext returns false. Lorsque l’énumérateur se trouve à cette position, les appels suivants à MoveNext retournent également false .When the enumerator is at this position, subsequent calls to MoveNext also return false. Si le dernier appel à MoveNext retourné false Current est non défini.If the last call to MoveNext returned false, Current is undefined. Pour attribuer une nouvelle fois Current au premier élément de la collection, vous pouvez appeler Reset suivi de MoveNext.To set Current to the first element of the collection again, you can call Reset followed by MoveNext.

Un énumérateur reste valide aussi longtemps que la collection demeure inchangée.An enumerator remains valid as long as the collection remains unchanged. Si des modifications sont apportées à la collection, telles que l’ajout, la modification ou la suppression d’éléments, l’énumérateur est définitivement invalidé et son comportement n’est pas défini.If changes are made to the collection, such as adding, modifying, or deleting elements, the enumerator is irrecoverably invalidated and its behavior is undefined.

Comme l’énumérateur ne dispose pas d’un accès exclusif à la collection, l’énumération d’une collection n’est pas intrinsèquement une procédure thread-safe.The enumerator does not have exclusive access to the collection; therefore, enumerating through a collection is intrinsically not a thread-safe procedure. Pour garantir la sécurité des threads pendant l'énumération, vous pouvez verrouiller la collection tout au long de cette opération.To guarantee thread safety during enumeration, you can lock the collection during the entire enumeration. Pour permettre à plusieurs threads d’accéder en lecture et en écriture à la collection, vous devez implémenter votre propre synchronisation.To allow the collection to be accessed by multiple threads for reading and writing, you must implement your own synchronization.

Cette méthode est une opération O (1).This method is an O(1) operation.

S’applique à

Voir aussi