HybridDictionary.Add(Object, Object) Méthode
Définition
Important
Certaines informations portent sur la préversion du produit qui est susceptible d’être en grande partie modifiée avant sa publication. Microsoft exclut toute garantie, expresse ou implicite, concernant les informations fournies ici.
Ajoute une entrée avec la clé et la valeur spécifiées dans HybridDictionary.
public:
virtual void Add(System::Object ^ key, System::Object ^ value);
public void Add (object key, object value);
public void Add (object key, object? value);
abstract member Add : obj * obj -> unit
override this.Add : obj * obj -> unit
Public Sub Add (key As Object, value As Object)
Paramètres
- key
- Object
Clé de l'entrée à ajouter.
- value
- Object
Valeur de l'entrée à ajouter. La valeur peut être null
.
Implémente
Exceptions
key
a la valeur null
.
Une entrée avec la même clé existe déjà dans HybridDictionary.
Exemples
L’exemple de code suivant ajoute à et supprime des éléments d’un HybridDictionary.
#using <System.dll>
using namespace System;
using namespace System::Collections;
using namespace System::Collections::Specialized;
void PrintKeysAndValues( IDictionary^ myCol )
{
Console::WriteLine( " KEY VALUE" );
IEnumerator^ myEnum = myCol->GetEnumerator();
while ( myEnum->MoveNext() )
{
DictionaryEntry de = safe_cast<DictionaryEntry>(myEnum->Current);
Console::WriteLine( " {0,-25} {1}", de.Key, de.Value );
}
Console::WriteLine();
}
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" );
// Displays the values in the HybridDictionary in three different ways.
Console::WriteLine( "Initial contents of the HybridDictionary:" );
PrintKeysAndValues( myCol );
// Deletes a key.
myCol->Remove( "Plums" );
Console::WriteLine( "The collection contains the following elements after removing \"Plums\":" );
PrintKeysAndValues( myCol );
// Clears the entire collection.
myCol->Clear();
Console::WriteLine( "The collection contains the following elements after it is cleared:" );
PrintKeysAndValues( myCol );
}
/*
This code produces output similar to the following:
Initial contents of the HybridDictionary:
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
The collection contains the following elements after removing "Plums":
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
Navel Oranges 1.29
Fuji Apples 1.29
The collection contains the following elements after it is cleared:
KEY VALUE
*/
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" );
// Displays the values in the HybridDictionary in three different ways.
Console.WriteLine( "Initial contents of the HybridDictionary:" );
PrintKeysAndValues( myCol );
// Deletes a key.
myCol.Remove( "Plums" );
Console.WriteLine( "The collection contains the following elements after removing \"Plums\":" );
PrintKeysAndValues( myCol );
// Clears the entire collection.
myCol.Clear();
Console.WriteLine( "The collection contains the following elements after it is cleared:" );
PrintKeysAndValues( myCol );
}
public static void PrintKeysAndValues( IDictionary myCol ) {
Console.WriteLine( " KEY VALUE" );
foreach ( DictionaryEntry de in myCol )
Console.WriteLine( " {0,-25} {1}", de.Key, de.Value );
Console.WriteLine();
}
}
/*
This code produces output similar to the following:
Initial contents of the HybridDictionary:
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
The collection contains the following elements after removing "Plums":
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
Navel Oranges 1.29
Fuji Apples 1.29
The collection contains the following elements after it is cleared:
KEY VALUE
*/
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")
' Displays the values in the HybridDictionary in three different ways.
Console.WriteLine("Initial contents of the HybridDictionary:")
PrintKeysAndValues(myCol)
' Deletes a key.
myCol.Remove("Plums")
Console.WriteLine("The collection contains the following elements after removing ""Plums"":")
PrintKeysAndValues(myCol)
' Clears the entire collection.
myCol.Clear()
Console.WriteLine("The collection contains the following elements after it is cleared:")
PrintKeysAndValues(myCol)
End Sub
Public Shared Sub PrintKeysAndValues(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
End Class
'This code produces output similar to the following:
'
'Initial contents of the HybridDictionary:
' 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
'
'The collection contains the following elements after removing "Plums":
' 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
' Navel Oranges 1.29
' Fuji Apples 1.29
'
'The collection contains the following elements after it is cleared:
' KEY VALUE
'
Remarques
Un objet qui n’a aucune corrélation entre son état et sa valeur de code de hachage ne doit généralement pas être utilisé comme clé. Par exemple, les objets String sont meilleurs que les objets StringBuilder pour une utilisation en tant que clés.
Une clé ne peut pas être null
, mais une valeur peut.
Vous pouvez également utiliser la Item[] propriété pour ajouter de nouveaux éléments en définissant la valeur d’une clé qui n’existe pas dans ; HybridDictionarypar exemple, myCollection["myNonexistentKey"] = myValue
. Toutefois, si la clé spécifiée existe déjà dans , la HybridDictionarydéfinition de la Item[] propriété remplace l’ancienne valeur. En revanche, la Add méthode ne modifie pas les éléments existants.
Lorsque le nombre d’éléments devient supérieur à la taille optimale pour un ListDictionary, les éléments sont copiés du ListDictionary vers un Hashtable. Toutefois, cela ne se produit qu’une seule fois. Si la collection est déjà stockée dans un Hashtable et que le nombre d’éléments est inférieur à la taille optimale pour un ListDictionary, la collection reste dans .Hashtable
Cette méthode est une opération O(1).