ListDictionary Construtores
Definição
Importante
Algumas informações se referem a produtos de pré-lançamento que podem ser substancialmente modificados antes do lançamento. A Microsoft não oferece garantias, expressas ou implícitas, das informações aqui fornecidas.
Inicializa uma nova instância da classe ListDictionary.
Sobrecargas
| ListDictionary() |
Cria um ListDictionary vazio usando o comparador padrão. |
| ListDictionary(IComparer) |
Cria um ListDictionary vazio usando o comparador especificado. |
ListDictionary()
- Origem:
- ListDictionary.cs
- Origem:
- ListDictionary.cs
- Origem:
- ListDictionary.cs
Cria um ListDictionary vazio usando o comparador padrão.
public:
ListDictionary();public ListDictionary ();Public Sub New ()Exemplos
O exemplo de código a seguir demonstra várias das propriedades e métodos de ListDictionary.
#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( ListDictionary^ myCol );
int main()
{
// Creates and initializes a new ListDictionary.
ListDictionary^ myCol = gcnew ListDictionary;
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" );
// 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 );
// Copies the ListDictionary 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,-25} {1}", myArr[ i ].Key, myArr[ i ].Value );
Console::WriteLine();
// Searches for a key.
if ( myCol->Contains( "Kiwis" ) )
Console::WriteLine( "The collection contains the key \"Kiwis\"." );
else
Console::WriteLine( "The collection does not contain the key \"Kiwis\"." );
Console::WriteLine();
// Deletes a key.
myCol->Remove( "Plums" );
Console::WriteLine( "The collection contains the following elements after removing \"Plums\":" );
PrintKeysAndValues2( myCol );
// Clears the entire collection.
myCol->Clear();
Console::WriteLine( "The collection contains the following elements after it is cleared:" );
PrintKeysAndValues2( myCol );
}
// 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.
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( ListDictionary^ 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 for each:
KEY VALUE
Braeburn Apples 1.49
Fuji Apples 1.29
Gala Apples 1.49
Golden Delicious Apples 1.29
Granny Smith Apples 0.89
Red Delicious Apples 0.99
Displays the elements using the IDictionaryEnumerator:
KEY VALUE
Braeburn Apples 1.49
Fuji Apples 1.29
Gala Apples 1.49
Golden Delicious Apples 1.29
Granny Smith Apples 0.89
Red Delicious Apples 0.99
Displays the elements using the Keys, Values, Count, and Item properties:
INDEX KEY VALUE
0 Braeburn Apples 1.49
1 Fuji Apples 1.29
2 Gala Apples 1.49
3 Golden Delicious Apples 1.29
4 Granny Smith Apples 0.89
5 Red Delicious Apples 0.99
Displays the elements in the array:
KEY VALUE
Braeburn Apples 1.49
Fuji Apples 1.29
Gala Apples 1.49
Golden Delicious Apples 1.29
Granny Smith Apples 0.89
Red Delicious Apples 0.99
The collection does not contain the key "Kiwis".
The collection contains the following elements after removing "Plums":
KEY VALUE
Braeburn Apples 1.49
Fuji Apples 1.29
Gala Apples 1.49
Golden Delicious Apples 1.29
Granny Smith Apples 0.89
Red Delicious Apples 0.99
The collection contains the following elements after it is cleared:
KEY VALUE
*/
using System;
using System.Collections;
using System.Collections.Specialized;
public class SamplesListDictionary {
public static void Main() {
// Creates and initializes a new ListDictionary.
ListDictionary myCol = new ListDictionary();
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" );
// 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 );
// Copies the ListDictionary 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,-25} {1}", myArr[i].Key, myArr[i].Value );
Console.WriteLine();
// Searches for a key.
if ( myCol.Contains( "Kiwis" ) )
Console.WriteLine( "The collection contains the key \"Kiwis\"." );
else
Console.WriteLine( "The collection does not contain the key \"Kiwis\"." );
Console.WriteLine();
// Deletes a key.
myCol.Remove( "Plums" );
Console.WriteLine( "The collection contains the following elements after removing \"Plums\":" );
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( 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( ListDictionary 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.
Note that because a dictionary is implemented for fast keyed access the order
of the items in the dictionary are not gauranteed and, as a result, should not
be depended on.
Displays the elements using foreach:
KEY VALUE
Braeburn Apples 1.49
Fuji Apples 1.29
Gala Apples 1.49
Golden Delicious Apples 1.29
Granny Smith Apples 0.89
Red Delicious Apples 0.99
Displays the elements using the IDictionaryEnumerator:
KEY VALUE
Braeburn Apples 1.49
Fuji Apples 1.29
Gala Apples 1.49
Golden Delicious Apples 1.29
Granny Smith Apples 0.89
Red Delicious Apples 0.99
Displays the elements using the Keys, Values, Count, and Item properties:
INDEX KEY VALUE
0 Braeburn Apples 1.49
1 Fuji Apples 1.29
2 Gala Apples 1.49
3 Golden Delicious Apples 1.29
4 Granny Smith Apples 0.89
5 Red Delicious Apples 0.99
Displays the elements in the array:
KEY VALUE
Braeburn Apples 1.49
Fuji Apples 1.29
Gala Apples 1.49
Golden Delicious Apples 1.29
Granny Smith Apples 0.89
Red Delicious Apples 0.99
The collection does not contain the key "Kiwis".
The collection contains the following elements after removing "Plums":
KEY VALUE
Braeburn Apples 1.49
Fuji Apples 1.29
Gala Apples 1.49
Golden Delicious Apples 1.29
Granny Smith Apples 0.89
Red Delicious Apples 0.99
The collection contains the following elements after it is cleared:
KEY VALUE
*/
Imports System.Collections
Imports System.Collections.Specialized
Public Class SamplesListDictionary
Public Shared Sub Main()
' Creates and initializes a new ListDictionary.
Dim myCol As New ListDictionary()
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")
' Display the contents of the collection using For Each. This is the preferred method.
Console.WriteLine("Displays the elements using For Each:")
PrintKeysAndValues(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)
' Copies the ListDictionary 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,-25} {1}", myArr(i).Key, myArr(i).Value)
Next i
Console.WriteLine()
' Searches for a key.
If myCol.Contains("Kiwis") Then
Console.WriteLine("The collection contains the key ""Kiwis"".")
Else
Console.WriteLine("The collection does not contain the key ""Kiwis"".")
End If
Console.WriteLine()
' 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
' 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 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
' 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 ListDictionary)
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 the following output.
'Note that because a dictionary is implemented for fast keyed access the order
'of the items in the dictionary are not gauranteed and, as a result, should not
'be depended on.
'
'Displays the elements using for each:
' KEY VALUE
' Braeburn Apples 1.49
' Fuji Apples 1.29
' Gala Apples 1.49
' Golden Delicious Apples 1.29
' Granny Smith Apples 0.89
' Red Delicious Apples 0.99
'
'Displays the elements using the IDictionaryEnumerator:
' KEY VALUE
' Braeburn Apples 1.49
' Fuji Apples 1.29
' Gala Apples 1.49
' Golden Delicious Apples 1.29
' Granny Smith Apples 0.89
' Red Delicious Apples 0.99
'
'Displays the elements using the Keys, Values, Count, and Item properties:
' INDEX KEY VALUE
' 0 Braeburn Apples 1.49
' 1 Fuji Apples 1.29
' 2 Gala Apples 1.49
' 3 Golden Delicious Apples 1.29
' 4 Granny Smith Apples 0.89
' 5 Red Delicious Apples 0.99
'
'Displays the elements in the array:
' KEY VALUE
' Braeburn Apples 1.49
' Fuji Apples 1.29
' Gala Apples 1.49
' Golden Delicious Apples 1.29
' Granny Smith Apples 0.89
' Red Delicious Apples 0.99
'
'The collection does not contain the key "Kiwis".
'
'The collection contains the following elements after removing "Plums":
' KEY VALUE
' Braeburn Apples 1.49
' Fuji Apples 1.29
' Gala Apples 1.49
' Golden Delicious Apples 1.29
' Granny Smith Apples 0.89
' Red Delicious Apples 0.99
'
'The collection contains the following elements after it is cleared:
' KEY VALUE
'
Comentários
O comparador determina se duas chaves são iguais. Cada chave em um ListDictionary deve ser exclusiva. O comparador padrão é a implementação da chave de Object.Equals.
Este construtor é uma operação O(1).
Confira também
Aplica-se a
ListDictionary(IComparer)
- Origem:
- ListDictionary.cs
- Origem:
- ListDictionary.cs
- Origem:
- ListDictionary.cs
Cria um ListDictionary vazio usando o comparador especificado.
public:
ListDictionary(System::Collections::IComparer ^ comparer);public ListDictionary (System.Collections.IComparer comparer);public ListDictionary (System.Collections.IComparer? comparer);new System.Collections.Specialized.ListDictionary : System.Collections.IComparer -> System.Collections.Specialized.ListDictionaryPublic Sub New (comparer As IComparer)Parâmetros
- comparer
- IComparer
O IComparer a ser usado para determinar se duas chaves são iguais.
- ou -
null para usar o comparador padrão, que é a implementação de cada chave de Equals(Object).
Comentários
O comparador determina se duas chaves são iguais. Cada chave em um ListDictionary deve ser exclusiva. O comparador padrão é a implementação da chave de Object.Equals.
O comparador personalizado permite cenários como fazer pesquisas com cadeias de caracteres que não diferenciam maiúsculas de minúsculas.
Este construtor é uma operação O(1).
Confira também
- IComparer
- Equals(Object)
- Executando operações de cadeia de caracteres que não levam em conta a cultura
Aplica-se a
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