Implementa una tabla hash con la clave y el valor con establecimiento inflexible de tipos que van a ser cadenas en lugar de objetos.
Espacio de nombres: System.Collections.Specialized
Ensamblado: System (en system.dll)
Visual Basic (Declaración)
<SerializableAttribute> _
Public Class StringDictionary
Implements IEnumerable
Dim instance As StringDictionary
[SerializableAttribute]
public class StringDictionary : IEnumerable
[SerializableAttribute]
public ref class StringDictionary : IEnumerable
/** @attribute SerializableAttribute() */
public class StringDictionary implements IEnumerable
SerializableAttribute
public class StringDictionary implements IEnumerable
Una clave no puede ser referencia de objeto null (Nothing en Visual Basic), pero un valor sí.
La clave se controla de forma que no se distinguen mayúsculas de minúsculas y se convierte a minúsculas antes de utilizarla con el diccionario de cadenas.
En el caso de la versión 1.0 de .NET Framework, esta clase utiliza comparaciones de cadenas que tienen en cuenta la referencia cultural. Sin embargo, en la versión 1.1 de .NET Framework y versiones posteriores, esta clase utiliza CultureInfo.InvariantCulture a la hora de comparar cadenas. Para obtener más información acerca de la forma en que la referencia cultural afecta a las comparaciones y a la ordenación, vea Comparar y ordenar datos para una referencia cultural específica y Realizar operaciones de cadenas que no distinguen entre referencias culturales.
En el código siguiente se muestran varios de los métodos y propiedades de la clase StringDictionary
Imports System
Imports System.Collections
Imports System.Collections.Specialized
Public Class SamplesStringDictionary
Public Shared Sub Main()
' Creates and initializes a new StringDictionary.
Dim myCol As New StringDictionary()
myCol.Add("red", "rojo")
myCol.Add("green", "verde")
myCol.Add("blue", "azul")
' 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 IEnumerator:")
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)
' Copies the StringDictionary to an array with DictionaryEntry elements.
Dim myArr(myCol.Count) As DictionaryEntry
myCol.CopyTo(myArr, 0)
' Displays the values in the array.
Console.WriteLine("Displays the elements in the array:")
Console.WriteLine(" KEY VALUE")
Dim i As Integer
For i = 0 To myArr.Length - 1
Console.WriteLine(" {0,-10} {1}", myArr(i).Key, myArr(i).Value)
Next i
Console.WriteLine()
' Searches for a value.
If myCol.ContainsValue("amarillo") Then
Console.WriteLine("The collection contains the value ""amarillo"".")
Else
Console.WriteLine("The collection does not contain the value ""amarillo"".")
End If
Console.WriteLine()
' Searches for a key and deletes it.
If myCol.ContainsKey("green") Then
myCol.Remove("green")
End If
Console.WriteLine("The collection contains the following elements after removing ""green"":")
PrintKeysAndValues1(myCol)
' Clears the entire collection.
myCol.Clear()
Console.WriteLine("The collection contains the following elements after it is cleared:")
PrintKeysAndValues1(myCol)
End Sub 'Main
' 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 StringDictionary)
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 'PrintKeysAndValues1
' 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 StringDictionary)
Dim myEnumerator As IEnumerator = myCol.GetEnumerator()
Dim de As DictionaryEntry
Console.WriteLine(" KEY VALUE")
While myEnumerator.MoveNext()
de = CType(myEnumerator.Current, DictionaryEntry)
Console.WriteLine(" {0,-25} {1}", de.Key, de.Value)
End While
Console.WriteLine()
End Sub 'PrintKeysAndValues2
' Uses the Keys, Values, Count, and Item properties.
Public Shared Sub PrintKeysAndValues3(myCol As StringDictionary)
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 'PrintKeysAndValues3
End Class 'SamplesStringDictionary
'This code produces the following output.
'
'Displays the elements using For Each:
' KEY VALUE
' red rojo
' blue azul
' green verde
'
'Displays the elements using the IEnumerator:
' KEY VALUE
' red rojo
' blue azul
' green verde
'
'Displays the elements using the Keys, Values, Count, and Item properties:
' INDEX KEY VALUE
' 0 red rojo
' 1 blue azul
' 2 green verde
'
'Displays the elements in the array:
' KEY VALUE
' red rojo
' blue azul
' green verde
'
'
'The collection does not contain the value "amarillo".
'
'The collection contains the following elements after removing "green":
' KEY VALUE
' red rojo
' blue azul
'
'The collection contains the following elements after it is cleared:
' KEY VALUE
using System;
using System.Collections;
using System.Collections.Specialized;
public class SamplesStringDictionary {
public static void Main() {
// Creates and initializes a new StringDictionary.
StringDictionary myCol = new StringDictionary();
myCol.Add( "red", "rojo" );
myCol.Add( "green", "verde" );
myCol.Add( "blue", "azul" );
// 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 IEnumerator:" );
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 );
// Copies the StringDictionary to an array with DictionaryEntry elements.
DictionaryEntry[] myArr = new DictionaryEntry[myCol.Count];
myCol.CopyTo( myArr, 0 );
// Displays the values in the array.
Console.WriteLine( "Displays the elements in the array:" );
Console.WriteLine( " KEY VALUE" );
for ( int i = 0; i < myArr.Length; i++ )
Console.WriteLine( " {0,-10} {1}", myArr[i].Key, myArr[i].Value );
Console.WriteLine();
// Searches for a value.
if ( myCol.ContainsValue( "amarillo" ) )
Console.WriteLine( "The collection contains the value \"amarillo\"." );
else
Console.WriteLine( "The collection does not contain the value \"amarillo\"." );
Console.WriteLine();
// Searches for a key and deletes it.
if ( myCol.ContainsKey( "green" ) )
myCol.Remove( "green" );
Console.WriteLine( "The collection contains the following elements after removing \"green\":" );
PrintKeysAndValues1( myCol );
// Clears the entire collection.
myCol.Clear();
Console.WriteLine( "The collection contains the following elements after it is cleared:" );
PrintKeysAndValues1( 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( StringDictionary 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( StringDictionary myCol ) {
IEnumerator myEnumerator = myCol.GetEnumerator();
DictionaryEntry de;
Console.WriteLine( " KEY VALUE" );
while ( myEnumerator.MoveNext() ) {
de = (DictionaryEntry) myEnumerator.Current;
Console.WriteLine( " {0,-25} {1}", de.Key, de.Value );
}
Console.WriteLine();
}
// Uses the Keys, Values, Count, and Item properties.
public static void PrintKeysAndValues3( StringDictionary 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 the following output.
Displays the elements using foreach:
KEY VALUE
red rojo
blue azul
green verde
Displays the elements using the IEnumerator:
KEY VALUE
red rojo
blue azul
green verde
Displays the elements using the Keys, Values, Count, and Item properties:
INDEX KEY VALUE
0 red rojo
1 blue azul
2 green verde
Displays the elements in the array:
KEY VALUE
red rojo
blue azul
green verde
The collection does not contain the value "amarillo".
The collection contains the following elements after removing "green":
KEY VALUE
red rojo
blue azul
The collection contains the following elements after it is cleared:
KEY VALUE
*/
#using <System.dll>
using namespace System;
using namespace System::Collections;
using namespace System::Collections::Specialized;
void PrintKeysAndValues2( StringDictionary^ myCol );
void PrintKeysAndValues3( StringDictionary^ myCol );
int main()
{
// Creates and initializes a new StringDictionary.
StringDictionary^ myCol = gcnew StringDictionary;
myCol->Add( "red", "rojo" );
myCol->Add( "green", "verde" );
myCol->Add( "blue", "azul" );
// Display the contents of the collection using the enumerator.
Console::WriteLine( "Displays the elements using the IEnumerator:" );
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 );
// Copies the StringDictionary to an array with DictionaryEntry elements.
array<DictionaryEntry>^myArr = gcnew array<DictionaryEntry>(myCol->Count);
myCol->CopyTo( myArr, 0 );
// Displays the values in the array.
Console::WriteLine( "Displays the elements in the array:" );
Console::WriteLine( " KEY VALUE" );
for ( int i = 0; i < myArr->Length; i++ )
Console::WriteLine( " {0,-10} {1}", myArr[ i ].Key, myArr[ i ].Value );
Console::WriteLine();
// Searches for a value.
if ( myCol->ContainsValue( "amarillo" ) )
Console::WriteLine( "The collection contains the value \"amarillo\"." );
else
Console::WriteLine( "The collection does not contain the value \"amarillo\"." );
Console::WriteLine();
// Searches for a key and deletes it.
if ( myCol->ContainsKey( "green" ) )
myCol->Remove( "green" );
Console::WriteLine( "The collection contains the following elements after removing \"green\":" );
PrintKeysAndValues2( myCol );
// Clears the entire collection.
myCol->Clear();
Console::WriteLine( "The collection contains the following elements after it is cleared:" );
PrintKeysAndValues2( myCol );
}
// Uses the enumerator.
void PrintKeysAndValues2( StringDictionary^ myCol )
{
IEnumerator^ myEnumerator = myCol->GetEnumerator();
DictionaryEntry de;
Console::WriteLine( " KEY VALUE" );
while ( myEnumerator->MoveNext() )
{
de = *dynamic_cast<DictionaryEntry^>(myEnumerator->Current);
Console::WriteLine( " {0,-25} {1}", de.Key, de.Value );
}
Console::WriteLine();
}
// Uses the Keys, Values, Count, and Item properties.
void PrintKeysAndValues3( StringDictionary^ 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 the following output.
Displays the elements using the IEnumerator:
KEY VALUE
red rojo
blue azul
green verde
Displays the elements using the Keys, Values, Count, and Item properties:
INDEX KEY VALUE
0 red rojo
1 blue azul
2 green verde
Displays the elements in the array:
KEY VALUE
red rojo
blue azul
green verde
The collection does not contain the value "amarillo".
The collection contains the following elements after removing "green":
KEY VALUE
red rojo
blue azul
The collection contains the following elements after it is cleared:
KEY VALUE
*/
import System.*;
import System.Collections.*;
import System.Collections.Specialized.*;
public class SamplesStringDictionary
{
public static void main(String[] args)
{
// Creates and initializes a new StringDictionary.
StringDictionary myCol = new StringDictionary();
myCol.Add("red", "rojo");
myCol.Add("green", "verde");
myCol.Add("blue", "azul");
// Display the contents of the collection using for loop.
// This is the preferred method.
Console.WriteLine("Displays the elements using for loop:");
PrintKeysAndValues1(myCol);
// Display the contents of the collection using the enumerator.
Console.WriteLine("Displays the elements using the IEnumerator:");
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);
// Copies the StringDictionary to an array with DictionaryEntry
// elements.
DictionaryEntry myArr[] = new DictionaryEntry[myCol.get_Count()];
myCol.CopyTo(myArr, 0);
// Displays the values in the array.
Console.WriteLine("Displays the elements in the array:");
Console.WriteLine(" KEY VALUE");
for(int i = 0; i < myArr.length; i++) {
Console.WriteLine(" {0,-10} {1}", myArr[i].get_Key(),
myArr[i].get_Value());
}
Console.WriteLine();
// Searches for a value.
if (myCol.ContainsValue("amarillo")) {
Console.WriteLine("The collection contains the value \"amarillo\".");
}
else {
Console.WriteLine("The collection does not contain the value "
+ "\"amarillo\".");
}
Console.WriteLine();
// Searches for a key and deletes it.
if (myCol.ContainsKey("green")) {
myCol.Remove("green");
}
Console.WriteLine("The collection contains the following elements after"
+ " removing \"green\":");
PrintKeysAndValues1(myCol);
// Clears the entire collection.
myCol.Clear();
Console.WriteLine("The collection contains the following elements"
+ " after it is cleared:");
PrintKeysAndValues1(myCol);
} //main
// Uses the for statement which hides the complexity of the enumerator.
// NOTE: The for statement is the preferred way of enumerating the contents
// of a collection.
public static void PrintKeysAndValues1(StringDictionary myCol)
{
String strValue;
String strKeys[] = new String[myCol.get_Count()];
myCol.get_Keys().CopyTo(strKeys, 0);
Console.WriteLine(" KEY VALUE");
for (int iCtr = 0; iCtr < myCol.get_Count(); iCtr++) {
strValue = myCol.get_Item(strKeys[iCtr]);
Console.WriteLine(" {0,-25} {1}", strKeys[iCtr], strValue);
}
Console.WriteLine();
} //PrintKeysAndValues1
// Uses the enumerator.
// NOTE: The for statement is the preferred way of enumerating the
// contents of a collection.
public static void PrintKeysAndValues2(StringDictionary myCol)
{
IEnumerator myEnumerator = myCol.GetEnumerator();
DictionaryEntry de;
Console.WriteLine(" KEY VALUE");
while(myEnumerator.MoveNext()) {
de =((DictionaryEntry)(myEnumerator.get_Current()));
Console.WriteLine(" {0,-25} {1}", de.get_Key(), de.get_Value());
}
Console.WriteLine();
} //PrintKeysAndValues2
// Uses the Keys, Values, Count, and Item properties.
public static void PrintKeysAndValues3(StringDictionary myCol)
{
String myKeys[] = new String[myCol.get_Count()];
myCol.get_Keys().CopyTo(myKeys, 0);
Console.WriteLine(" INDEX KEY VALUE");
for(int i = 0; i < myCol.get_Count(); i++) {
Console.WriteLine(" {0,-5} {1,-25} {2}", (Int32)i, myKeys[i],
myCol.get_Item(myKeys[i]));
}
Console.WriteLine();
} //PrintKeysAndValues3
} //SamplesStringDictionary
/*
This code produces the following output.
Displays the elements using for loop:
KEY VALUE
red rojo
blue azul
green verde
Displays the elements using the IEnumerator:
KEY VALUE
red rojo
blue azul
green verde
Displays the elements using the Keys, Values, Count, and Item properties:
INDEX KEY VALUE
0 red rojo
1 blue azul
2 green verde
Displays the elements in the array:
KEY VALUE
red rojo
blue azul
green verde
The collection does not contain the value "amarillo".
The collection contains the following elements after removing "green":
KEY VALUE
red rojo
blue azul
The collection contains the following elements after it is cleared:
KEY VALUE
*/
System.Object
System.Collections.Specialized.StringDictionary
Seguridad para subprocesos
Los miembros estáticos públicos (Shared en Visual Basic) de este tipo son seguros para la ejecución de subprocesos. No se garantiza que los miembros de instancias sean seguros para la ejecución de subprocesos.
Esta implementación no proporciona un contenedor sincronizado (seguro para la ejecución de subprocesos) para una clase StringDictionary, pero las clases derivadas pueden crear sus propias versiones sincronizadas de StringDictionary mediante la propiedad SyncRoot.
La enumeración a través de una colección es un procedimiento sin seguridad intrínseca para la ejecución de subprocesos. Aunque una colección esté sincronizada, otros subprocesos pueden seguir modificándola, lo que hace que el enumerador produzca una excepción. Con el fin de garantizar la seguridad para la ejecución de subprocesos durante la enumeración, es posible bloquear la colección durante toda la enumeración o detectar las excepciones debidas a cambios efectuados por otros subprocesos.
Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium, Windows Mobile para Pocket PC, Windows Mobile para Smartphone, Windows Server 2003, Windows XP Media Center, Windows XP Professional x64, Windows XP SP2, Windows XP Starter Edition
.NET Framework no admite todas las versiones de cada plataforma. Para obtener una lista de las versiones admitidas, vea Requisitos del sistema.
.NET Framework
Compatible con: 2.0, 1.1, 1.0
.NET Compact Framework
Compatible con: 2.0