StringCollection Classe

Definição

Representa uma coleção de cadeias de caracteres.Represents a collection of strings.

public ref class StringCollection : System::Collections::IList
public class StringCollection : System.Collections.IList
[System.Serializable]
public class StringCollection : System.Collections.IList
type StringCollection = class
    interface ICollection
    interface IEnumerable
    interface IList
type StringCollection = class
    interface IList
    interface ICollection
    interface IEnumerable
Public Class StringCollection
Implements IList
Herança
StringCollection
Derivado
Atributos
Implementações

Exemplos

O exemplo de código a seguir demonstra várias das propriedades e métodos de StringCollection.The following code example demonstrates several of the properties and methods of StringCollection.

#using <System.dll>

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

void PrintValues1( StringCollection^ myCol );
void PrintValues2( StringCollection^ myCol );
void PrintValues3( StringCollection^ myCol );

int main()
{
   
   // Create and initializes a new StringCollection.
   StringCollection^ myCol = gcnew StringCollection;
   
   // Add a range of elements from an array to the end of the StringCollection.
   array<String^>^myArr = {"RED","orange","yellow","RED","green","blue","RED","indigo","violet","RED"};
   myCol->AddRange( myArr );
   
   // Display the contents of the collection using for each. This is the preferred method.
   Console::WriteLine( "Displays the elements using for each:" );
   PrintValues1( myCol );

   // Display the contents of the collection using the enumerator.
   Console::WriteLine( "Displays the elements using the IEnumerator:" );
   PrintValues2( myCol );
   
   // Display the contents of the collection using the Count and Item properties.
   Console::WriteLine( "Displays the elements using the Count and Item properties:" );
   PrintValues3( myCol );
   
   // Add one element to the end of the StringCollection and insert another at index 3.
   myCol->Add( "* white" );
   myCol->Insert( 3, "* gray" );
   Console::WriteLine( "After adding \"* white\" to the end and inserting \"* gray\" at index 3:" );
   PrintValues1( myCol );
   
   // Remove one element from the StringCollection.
   myCol->Remove( "yellow" );
   Console::WriteLine( "After removing \"yellow\":" );
   PrintValues1( myCol );
   
   // Remove all occurrences of a value from the StringCollection.
   int i = myCol->IndexOf( "RED" );
   while ( i > -1 )
   {
      myCol->RemoveAt( i );
      i = myCol->IndexOf( "RED" );
   }

   
   // Verify that all occurrences of "RED" are gone.
   if ( myCol->Contains( "RED" ) )
      Console::WriteLine( "*** The collection still contains \"RED\"." );

   Console::WriteLine( "After removing all occurrences of \"RED\":" );
   PrintValues1( myCol );
   
   // Copy the collection to a new array starting at index 0.
   array<String^>^myArr2 = gcnew array<String^>(myCol->Count);
   myCol->CopyTo( myArr2, 0 );
   Console::WriteLine( "The new array contains:" );
   for ( i = 0; i < myArr2->Length; i++ )
   {
      Console::WriteLine( "   [{0}] {1}", i, myArr2[ i ] );

   }
   Console::WriteLine();
   
   // Clears the entire collection.
   myCol->Clear();
   Console::WriteLine( "After clearing the collection:" );
   PrintValues1( 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 PrintValues1( StringCollection^ myCol )  {
   for each ( Object^ obj in myCol )
      Console::WriteLine( "   {0}", obj );
   Console::WriteLine();
}

// Uses the enumerator. 
void PrintValues2( StringCollection^ myCol )
{
   StringEnumerator^ myEnumerator = myCol->GetEnumerator();
   while ( myEnumerator->MoveNext() )
      Console::WriteLine( "   {0}", myEnumerator->Current );

   Console::WriteLine();
}


// Uses the Count and Item properties.
void PrintValues3( StringCollection^ myCol )
{
   for ( int i = 0; i < myCol->Count; i++ )
      Console::WriteLine( "   {0}", myCol[ i ] );
   Console::WriteLine();
}

/*
This code produces the following output.

Displays the elements using the IEnumerator:
   RED
   orange
   yellow
   RED
   green
   blue
   RED
   indigo
   violet
   RED

Displays the elements using the Count and Item properties:
   RED
   orange
   yellow
   RED
   green
   blue
   RED
   indigo
   violet
   RED

After adding "* white" to the end and inserting "* gray" at index 3:
   RED
   orange
   yellow
   * gray
   RED
   green
   blue
   RED
   indigo
   violet
   RED
   * white

After removing "yellow":
   RED
   orange
   * gray
   RED
   green
   blue
   RED
   indigo
   violet
   RED
   * white

After removing all occurrences of "RED":
   orange
   * gray
   green
   blue
   indigo
   violet
   * white

The new array contains:
   [0] orange
   [1] * gray
   [2] green
   [3] blue
   [4] indigo
   [5] violet
   [6] * white

After clearing the collection:

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

public class SamplesStringCollection  {

   public static void Main()  {

      // Create and initializes a new StringCollection.
      StringCollection myCol = new StringCollection();

      // Add a range of elements from an array to the end of the StringCollection.
      String[] myArr = new String[] { "RED", "orange", "yellow", "RED", "green", "blue", "RED", "indigo", "violet", "RED" };
      myCol.AddRange( myArr );

      // Display the contents of the collection using foreach. This is the preferred method.
      Console.WriteLine( "Displays the elements using foreach:" );
      PrintValues1( myCol );

      // Display the contents of the collection using the enumerator.
      Console.WriteLine( "Displays the elements using the IEnumerator:" );
      PrintValues2( myCol );

      // Display the contents of the collection using the Count and Item properties.
      Console.WriteLine( "Displays the elements using the Count and Item properties:" );
      PrintValues3( myCol );

      // Add one element to the end of the StringCollection and insert another at index 3.
      myCol.Add( "* white" );
      myCol.Insert( 3, "* gray" );

      Console.WriteLine( "After adding \"* white\" to the end and inserting \"* gray\" at index 3:" );
      PrintValues1( myCol );

      // Remove one element from the StringCollection.
      myCol.Remove( "yellow" );

      Console.WriteLine( "After removing \"yellow\":" );
      PrintValues1( myCol );

      // Remove all occurrences of a value from the StringCollection.
      int i = myCol.IndexOf( "RED" );
      while ( i > -1 )  {
         myCol.RemoveAt( i );
         i = myCol.IndexOf( "RED" );
      }

      // Verify that all occurrences of "RED" are gone.
      if ( myCol.Contains( "RED" ) )
         Console.WriteLine( "*** The collection still contains \"RED\"." );

      Console.WriteLine( "After removing all occurrences of \"RED\":" );
      PrintValues1( myCol );

      // Copy the collection to a new array starting at index 0.
      String[] myArr2 = new String[myCol.Count];
      myCol.CopyTo( myArr2, 0 );

      Console.WriteLine( "The new array contains:" );
      for ( i = 0; i < myArr2.Length; i++ )  {
         Console.WriteLine( "   [{0}] {1}", i, myArr2[i] );
      }
      Console.WriteLine();

      // Clears the entire collection.
      myCol.Clear();

      Console.WriteLine( "After clearing the collection:" );
      PrintValues1( 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 PrintValues1( StringCollection myCol )  {
      foreach ( Object obj in myCol )
         Console.WriteLine( "   {0}", obj );
      Console.WriteLine();
   }

   // Uses the enumerator. 
   // NOTE: The foreach statement is the preferred way of enumerating the contents of a collection.
   public static void PrintValues2( StringCollection myCol )  {
      StringEnumerator myEnumerator = myCol.GetEnumerator();
      while ( myEnumerator.MoveNext() )
         Console.WriteLine( "   {0}", myEnumerator.Current );
      Console.WriteLine();
   }

   // Uses the Count and Item properties.
   public static void PrintValues3( StringCollection myCol )  {
      for ( int i = 0; i < myCol.Count; i++ )
         Console.WriteLine( "   {0}", myCol[i] );
      Console.WriteLine();
   }
}

/*
This code produces the following output.

Displays the elements using foreach:
   RED
   orange
   yellow
   RED
   green
   blue
   RED
   indigo
   violet
   RED

Displays the elements using the IEnumerator:
   RED
   orange
   yellow
   RED
   green
   blue
   RED
   indigo
   violet
   RED

Displays the elements using the Count and Item properties:
   RED
   orange
   yellow
   RED
   green
   blue
   RED
   indigo
   violet
   RED

After adding "* white" to the end and inserting "* gray" at index 3:
   RED
   orange
   yellow
   * gray
   RED
   green
   blue
   RED
   indigo
   violet
   RED
   * white

After removing "yellow":
   RED
   orange
   * gray
   RED
   green
   blue
   RED
   indigo
   violet
   RED
   * white

After removing all occurrences of "RED":
   orange
   * gray
   green
   blue
   indigo
   violet
   * white

The new array contains:
   [0] orange
   [1] * gray
   [2] green
   [3] blue
   [4] indigo
   [5] violet
   [6] * white

After clearing the collection:

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

Public Class SamplesStringCollection

   Public Shared Sub Main()

      ' Create and initializes a new StringCollection.
      Dim myCol As New StringCollection()

      ' Add a range of elements from an array to the end of the StringCollection.
      Dim myArr() As String = {"RED", "orange", "yellow", "RED", "green", "blue", "RED", "indigo", "violet", "RED"}
      myCol.AddRange(myArr)

      ' Display the contents of the collection using foreach. This is the preferred method.
      Console.WriteLine("Displays the elements using foreach:")
      PrintValues1(myCol)

      ' Display the contents of the collection using the enumerator.
      Console.WriteLine("Displays the elements using the IEnumerator:")
      PrintValues2(myCol)

      ' Display the contents of the collection using the Count and Item properties.
      Console.WriteLine("Displays the elements using the Count and Item properties:")
      PrintValues3(myCol)

      ' Add one element to the end of the StringCollection and insert another at index 3.
      myCol.Add("* white")
      myCol.Insert(3, "* gray")

      Console.WriteLine("After adding ""* white"" to the end and inserting ""* gray"" at index 3:")
      PrintValues1(myCol)

      ' Remove one element from the StringCollection.
      myCol.Remove("yellow")

      Console.WriteLine("After removing ""yellow"":")
      PrintValues1(myCol)

      ' Remove all occurrences of a value from the StringCollection.
      Dim i As Integer = myCol.IndexOf("RED")
      While i > - 1
         myCol.RemoveAt(i)
         i = myCol.IndexOf("RED")
      End While

      ' Verify that all occurrences of "RED" are gone.
      If myCol.Contains("RED") Then
         Console.WriteLine("*** The collection still contains ""RED"".")
      End If 
      Console.WriteLine("After removing all occurrences of ""RED"":")
      PrintValues1(myCol)

      ' Copy the collection to a new array starting at index 0.
      Dim myArr2(myCol.Count) As String
      myCol.CopyTo(myArr2, 0)

      Console.WriteLine("The new array contains:")
      For i = 0 To myArr2.Length - 1
         Console.WriteLine("   [{0}] {1}", i, myArr2(i))
      Next i
      Console.WriteLine()

      ' Clears the entire collection.
      myCol.Clear()

      Console.WriteLine("After clearing the collection:")
      PrintValues1(myCol)
   End Sub


   ' 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 Shared Sub PrintValues1(myCol As StringCollection)
      Dim obj As [Object]
      For Each obj In  myCol
         Console.WriteLine("   {0}", obj)
      Next obj
      Console.WriteLine()
   End Sub


   ' Uses the enumerator. 
   ' NOTE: The foreach statement is the preferred way of enumerating the contents of a collection.
   Public Shared Sub PrintValues2(myCol As StringCollection)
      Dim myEnumerator As StringEnumerator = myCol.GetEnumerator()
      While myEnumerator.MoveNext()
         Console.WriteLine("   {0}", myEnumerator.Current)
      End While
      Console.WriteLine()
   End Sub


   ' Uses the Count and Item properties.
   Public Shared Sub PrintValues3(myCol As StringCollection)
      Dim i As Integer
      For i = 0 To myCol.Count - 1
         Console.WriteLine("   {0}", myCol(i))
      Next i
      Console.WriteLine()
   End Sub

End Class


'This code produces the following output.
'
'Displays the elements using foreach:
'   RED
'   orange
'   yellow
'   RED
'   green
'   blue
'   RED
'   indigo
'   violet
'   RED
'
'Displays the elements using the IEnumerator:
'   RED
'   orange
'   yellow
'   RED
'   green
'   blue
'   RED
'   indigo
'   violet
'   RED
'
'Displays the elements using the Count and Item properties:
'   RED
'   orange
'   yellow
'   RED
'   green
'   blue
'   RED
'   indigo
'   violet
'   RED
'
'After adding "* white" to the end and inserting "* gray" at index 3:
'   RED
'   orange
'   yellow
'   * gray
'   RED
'   green
'   blue
'   RED
'   indigo
'   violet
'   RED
'   * white
'
'After removing "yellow":
'   RED
'   orange
'   * gray
'   RED
'   green
'   blue
'   RED
'   indigo
'   violet
'   RED
'   * white
'
'After removing all occurrences of "RED":
'   orange
'   * gray
'   green
'   blue
'   indigo
'   violet
'   * white
'
'The new array contains:
'   [0] orange
'   [1] * gray
'   [2] green
'   [3] blue
'   [4] indigo
'   [5] violet
'   [6] * white
'
'After clearing the collection:
'

Comentários

StringCollection aceita null como um valor válido e permite elementos duplicados.StringCollection accepts null as a valid value and allows duplicate elements.

Comparações de cadeia de caracteres diferenciam maiúsculas de minúsculas.String comparisons are case-sensitive.

Elementos nesta coleção podem ser acessados usando um índice de número inteiro.Elements in this collection can be accessed using an integer index. Os índices nesta coleção são baseados em zero.Indexes in this collection are zero-based.

Construtores

StringCollection()

Inicializa uma nova instância da classe StringCollection.Initializes a new instance of the StringCollection class.

Propriedades

Count

Obtém o número de cadeias de caracteres contidas no StringCollection.Gets the number of strings contained in the StringCollection.

IsReadOnly

Obtém um valor que indica se o StringCollection é somente leitura.Gets a value indicating whether the StringCollection is read-only.

IsSynchronized

Obtém um valor que indica se o acesso à StringCollection é sincronizado (thread-safe).Gets a value indicating whether access to the StringCollection is synchronized (thread safe).

Item[Int32]

Obtém ou define o elemento no índice especificado.Gets or sets the element at the specified index.

SyncRoot

Obtém um objeto que pode ser usado para sincronizar o acesso ao StringCollection.Gets an object that can be used to synchronize access to the StringCollection.

Métodos

Add(String)

Adiciona uma cadeia de caracteres ao final do StringCollection.Adds a string to the end of the StringCollection.

AddRange(String[])

Copia os elementos de uma matriz de cadeia de caracteres para o final do StringCollection.Copies the elements of a string array to the end of the StringCollection.

Clear()

Remove todas as cadeias de caracteres do StringCollection.Removes all the strings from the StringCollection.

Contains(String)

Determina se a cadeia de caracteres especificada está na StringCollection.Determines whether the specified string is in the StringCollection.

CopyTo(String[], Int32)

Copia todo os valores de StringCollection em uma matriz unidimensional de cadeias de caracteres, começando no índice especificado da matriz de destino.Copies the entire StringCollection values to a one-dimensional array of strings, starting at the specified index of the target array.

Equals(Object)

Determina se o objeto especificado é igual ao objeto atual.Determines whether the specified object is equal to the current object.

(Herdado de Object)
GetEnumerator()

Retorna um StringEnumerator que itera por meio de StringCollection.Returns a StringEnumerator that iterates through the StringCollection.

GetHashCode()

Serve como a função de hash padrão.Serves as the default hash function.

(Herdado de Object)
GetType()

Obtém o Type da instância atual.Gets the Type of the current instance.

(Herdado de Object)
IndexOf(String)

Pesquisa a cadeia de caracteres especificada e retorna o índice de base zero da primeira ocorrência dentro da StringCollection.Searches for the specified string and returns the zero-based index of the first occurrence within the StringCollection.

Insert(Int32, String)

Insere uma cadeia de caracteres no StringCollection do índice especificado.Inserts a string into the StringCollection at the specified index.

MemberwiseClone()

Cria uma cópia superficial do Object atual.Creates a shallow copy of the current Object.

(Herdado de Object)
Remove(String)

Remove a primeira ocorrência de uma cadeia de caracteres específica do StringCollection.Removes the first occurrence of a specific string from the StringCollection.

RemoveAt(Int32)

Remove a cadeia de caracteres no índice especificado do StringCollection.Removes the string at the specified index of the StringCollection.

ToString()

Retorna uma cadeia de caracteres que representa o objeto atual.Returns a string that represents the current object.

(Herdado de Object)

Implantações explícitas de interface

ICollection.CopyTo(Array, Int32)

Copia todo o StringCollection em um Array unidimensional compatível, começando no índice especificado da matriz de destino.Copies the entire StringCollection to a compatible one-dimensional Array, starting at the specified index of the target array.

IEnumerable.GetEnumerator()

Retorna um IEnumerator que itera por meio de StringCollection.Returns a IEnumerator that iterates through the StringCollection.

IList.Add(Object)

Adiciona um objeto ao final do StringCollection.Adds an object to the end of the StringCollection.

IList.Contains(Object)

Determina se um elemento está no StringCollection.Determines whether an element is in the StringCollection.

IList.IndexOf(Object)

Pesquisa o Object especificado e retorna o índice de base zero da primeira ocorrência dentro de todo o StringCollection.Searches for the specified Object and returns the zero-based index of the first occurrence within the entire StringCollection.

IList.Insert(Int32, Object)

Insere um elemento no StringCollection, no índice especificado.Inserts an element into the StringCollection at the specified index.

IList.IsFixedSize

Obtém um valor que indica se o objeto StringCollection tem um tamanho fixo.Gets a value indicating whether the StringCollection object has a fixed size.

IList.IsReadOnly

Obtém um valor que indica se o objeto StringCollection é somente leitura.Gets a value indicating whether the StringCollection object is read-only.

IList.Item[Int32]

Obtém ou define o elemento no índice especificado.Gets or sets the element at the specified index.

IList.Remove(Object)

Remove a primeira ocorrência de um objeto específico do StringCollection.Removes the first occurrence of a specific object from the StringCollection.

Métodos de Extensão

Cast<TResult>(IEnumerable)

Converte os elementos de um IEnumerable para o tipo especificado.Casts the elements of an IEnumerable to the specified type.

OfType<TResult>(IEnumerable)

Filtra os elementos de um IEnumerable com base em um tipo especificado.Filters the elements of an IEnumerable based on a specified type.

AsParallel(IEnumerable)

Habilita a paralelização de uma consulta.Enables parallelization of a query.

AsQueryable(IEnumerable)

Converte um IEnumerable em um IQueryable.Converts an IEnumerable to an IQueryable.

Aplica-se a

Acesso thread-safe

Os membros estáticos públicos (Shared no Visual Basic) desse são thread-safe.Public static (Shared in Visual Basic) members of this type are thread safe. Não há garantia de que qualquer membro de instância seja thread-safe.Any instance members are not guaranteed to be thread safe.

Essa implementação não fornece um wrapper sincronizado (thread-safe) para um StringCollection, mas classes derivadas podem criar suas próprias versões sincronizadas do StringCollection usando a propriedade SyncRoot.This implementation does not provide a synchronized (thread safe) wrapper for a StringCollection, but derived classes can create their own synchronized versions of the StringCollection using the SyncRoot property.

A enumeração por meio de uma coleção é intrinsecamente não um procedimento de thread seguro.Enumerating through a collection is intrinsically not a thread safe procedure. Mesmo quando uma coleção está sincronizada, outros threads ainda podem modificar a coleção, o que faz o enumerador lançar uma exceção.Even when a collection is synchronized, other threads can still modify the collection, which causes the enumerator to throw an exception. Para garantir thread-safe durante a enumeração, é possível bloquear a coleção durante toda a enumeração ou verificar as exceções resultantes das alterações feitas por outros threads.To guarantee thread safety during enumeration, you can either lock the collection during the entire enumeration or catch the exceptions resulting from changes made by other threads.

Veja também