ArrayList.Insert(Int32, Object) Método

public:
 virtual void Insert(int index, System::Object ^ value);

public virtual void Insert(int index, object value);

abstract member Insert : int * obj -> unit
override this.Insert : int * obj -> unit

Public Overridable Sub Insert (index As Integer, value As Object)

Parâmetros

Implementações

Exceções

Exemplos

O exemplo de código a seguir mostra como inserir elementos no ArrayList.

using System;
using System.Collections;
public class SamplesArrayList  {

   public static void Main()  {

      // Creates and initializes a new ArrayList using Insert instead of Add.
      ArrayList myAL = new ArrayList();
      myAL.Insert( 0, "The" );
      myAL.Insert( 1, "fox" );
      myAL.Insert( 2, "jumps" );
      myAL.Insert( 3, "over" );
      myAL.Insert( 4, "the" );
      myAL.Insert( 5, "dog" );

      // Creates and initializes a new Queue.
      Queue myQueue = new Queue();
      myQueue.Enqueue( "quick" );
      myQueue.Enqueue( "brown" );

      // Displays the ArrayList and the Queue.
      Console.WriteLine( "The ArrayList initially contains the following:" );
      PrintValues( myAL );
      Console.WriteLine( "The Queue initially contains the following:" );
      PrintValues( myQueue );

      // Copies the Queue elements to the ArrayList at index 1.
      myAL.InsertRange( 1, myQueue );

      // Displays the ArrayList.
      Console.WriteLine( "After adding the Queue, the ArrayList now contains:" );
      PrintValues( myAL );

      // Search for "dog" and add "lazy" before it.
      myAL.Insert( myAL.IndexOf( "dog" ), "lazy" );

      // Displays the ArrayList.
      Console.WriteLine( "After adding \"lazy\", the ArrayList now contains:" );
      PrintValues( myAL );

      // Add "!!!" at the end.
      myAL.Insert( myAL.Count, "!!!" );

      // Displays the ArrayList.
      Console.WriteLine( "After adding \"!!!\", the ArrayList now contains:" );
      PrintValues( myAL );

      // Inserting an element beyond Count throws an exception.
      try  {
         myAL.Insert( myAL.Count+1, "anystring" );
      } catch ( Exception myException )  {
         Console.WriteLine("Exception: " + myException.ToString());
      }
   }

   public static void PrintValues( IEnumerable myList )  {
      foreach ( Object obj in myList )
         Console.Write( "   {0}", obj );
      Console.WriteLine();
   }
}
/*
This code produces the following output.

The ArrayList initially contains the following:
   The   fox   jumps   over   the   dog
The Queue initially contains the following:
   quick   brown
After adding the Queue, the ArrayList now contains:
   The   quick   brown   fox   jumps   over   the   dog
After adding "lazy", the ArrayList now contains:
   The   quick   brown   fox   jumps   over   the   lazy   dog
After adding "!!!", the ArrayList now contains:
   The   quick   brown   fox   jumps   over   the   lazy   dog   !!!
Exception: System.ArgumentOutOfRangeException: Insertion index was out of range.  Must be non-negative and less than or equal to size.
Parameter name: index
   at System.Collections.ArrayList.Insert(int index, Object value)
   at SamplesArrayList.Main()
*/

Imports System.Collections

Public Class SamplesArrayList    
    
    Public Shared Sub Main()
        
        ' Creates and initializes a new ArrayList using Insert instead of Add.
        Dim myAL As New ArrayList()
        myAL.Insert(0, "The")
        myAL.Insert(1, "fox")
        myAL.Insert(2, "jumps")
        myAL.Insert(3, "over")
        myAL.Insert(4, "the")
        myAL.Insert(5, "dog")
        
        ' Creates and initializes a new Queue.
        Dim myQueue As New Queue()
        myQueue.Enqueue("quick")
        myQueue.Enqueue("brown")
        
        ' Displays the ArrayList and the Queue.
        Console.WriteLine("The ArrayList initially contains the following:")
        PrintValues(myAL)
        Console.WriteLine("The Queue initially contains the following:")
        PrintValues(myQueue)
        
        ' Copies the Queue elements to the ArrayList at index 1.
        myAL.InsertRange(1, myQueue)
        
        ' Displays the ArrayList.
        Console.WriteLine("After adding the Queue, the ArrayList now contains:")
        PrintValues(myAL)
        
        ' Search for "dog" and add "lazy" before it.
        myAL.Insert(myAL.IndexOf("dog"), "lazy")
        
        ' Displays the ArrayList.
        Console.WriteLine("After adding ""lazy"", the ArrayList now contains:")
        PrintValues(myAL)
        
        ' Add "!!!" at the end.
        myAL.Insert(myAL.Count, "!!!")
        
        ' Displays the ArrayList.
        Console.WriteLine("After adding ""!!!"", the ArrayList now contains:")
        PrintValues(myAL)
        
        ' Inserting an element beyond Count throws an exception.
        Try
            myAL.Insert(myAL.Count + 1, "anystring")
        Catch myException As Exception
            Console.WriteLine("Exception: " + myException.ToString())
        End Try
    End Sub    
    
    Public Shared Sub PrintValues(myList As IEnumerable)
        Dim obj As [Object]
        For Each obj In  myList
            Console.Write("   {0}", obj)
        Next obj
        Console.WriteLine()
    End Sub

End Class

' This code produces the following output.
' 
' The ArrayList initially contains the following:
'     The    fox    jumps    over    the    dog
' The Queue initially contains the following:
'     quick    brown
' After adding the Queue, the ArrayList now contains:
'     The    quick    brown    fox    jumps    over    the    dog
' After adding "lazy", the ArrayList now contains:
'     The    quick    brown    fox    jumps    over    the    lazy    dog
' After adding "!!!", the ArrayList now contains:
'     The    quick    brown    fox    jumps    over    the    lazy    dog    !!!
' Exception: System.ArgumentOutOfRangeException: Insertion index was out of range.  Must be non-negative and less than or equal to size.
' Parameter name: index
'    at System.Collections.ArrayList.Insert(Int32 index, Object value)
'    at SamplesArrayList.Main()

Comentários

ArrayList null aceita como um valor válido e permite elementos duplicados.

Se Count já for Capacityigual, a capacidade da ArrayList matriz será aumentada realocando automaticamente a matriz interna e os elementos existentes serão copiados para a nova matriz antes que o novo elemento seja adicionado.

Se index for igual a Count, value será adicionado ao final de ArrayList.

Em coleções de elementos contíguos, como listas, os elementos que seguem o ponto de inserção se movem para baixo para acomodar o novo elemento. Se a coleção for indexada, os índices dos elementos movidos também serão atualizados. Esse comportamento não se aplica a coleções em que os elementos são agrupados conceitualmente em buckets, como uma tabela de hash.

Esse método é uma O(n) operação, onde n está Count.

Confira também

• InsertRange(Int32, ICollection)
• Add(Object)
• Remove(Object)