ArrayList.Insert(Int32, Object) Método

Definición

Espacio de nombres:

System.Collections

Ensamblado:

System.Runtime.dll

Source:

ArrayList.cs

Inserta un elemento en ArrayList en el índice especificado.

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)

Parámetros

index

Int32

Índice basado en cero en el que debe insertarse value.

value

Object

Object que se va a insertar. El valor puede ser null.

Implementaciones

Insert(Int32, Object)

Excepciones

ArgumentOutOfRangeException

index es menor que cero.

O bien

index es mayor que Count.

NotSupportedException

ArrayList es de solo lectura.

o bien

ArrayList tiene un tamaño fijo.

Ejemplos

En el ejemplo de código siguiente se muestra cómo insertar elementos en .ArrayList

using namespace System;
using namespace System::Collections;
void PrintValues( IEnumerable^ myList );
int main()
{
   
   // Creates and initializes a new ArrayList using Insert instead of Add.
   ArrayList^ myAL = gcnew 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 = gcnew 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: {0}", myException );
   }

}

void PrintValues( IEnumerable^ myList )
{
   IEnumerator^ myEnum = myList->GetEnumerator();
   while ( myEnum->MoveNext() )
   {
      Object^ obj = safe_cast<Object^>(myEnum->Current);
      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(Int32 index, Object value)
    at SamplesArrayList.Main()
 */

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()

Comentarios

ArrayListnull acepta como un valor válido y permite elementos duplicados.

Si Count ya es Capacityigual a , la capacidad de se incrementa mediante la reasignación automática de ArrayList la matriz interna y los elementos existentes se copian en la nueva matriz antes de agregar el nuevo elemento.

Si index es igual a Count, value se agrega al final de ArrayList.

En colecciones de elementos contiguos, como listas, los elementos que van a continuación del punto de inserción se desplazan hacia abajo para alojar el elemento nuevo. Si la colección está indizada, también se actualizan los índices de los elementos que se han movido. Este comportamiento no se aplica a las colecciones cuyos elementos se agrupan conceptualmente en sectores de almacenamiento, como una tabla hash.

Este método es una O(n) operación, donde n es Count.

Consulte también

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