Array.Resize<T>(T[], Int32) Método

Referencia

Definición

Espacio de nombres:: System

Ensamblado:: System.Runtime.dll

Ensamblado:: mscorlib.dll

Ensamblado:: netstandard.dll

Importante

Parte de la información hace referencia a la versión preliminar del producto, que puede haberse modificado sustancialmente antes de lanzar la versión definitiva. Microsoft no otorga ninguna garantía, explícita o implícita, con respecto a la información proporcionada aquí.

Cambia el número de elementos de una matriz unidimensional al nuevo tamaño especificado.

public:
generic <typename T>
 static void Resize(cli::array <T> ^ % array, int newSize);

public static void Resize<T> (ref T[] array, int newSize);

public static void Resize<T> (ref T[]? array, int newSize);

static member Resize : T[] * int -> unit

Public Shared Sub Resize(Of T) (ByRef array As T(), newSize As Integer)

Parámetros de tipo

T

Tipo de los elementos de la matriz.

Parámetros

array: T[]

Matriz unidimensional de base cero a la que se va a cambiar el tamaño o null para crear una nueva matriz con el tamaño especificado.

newSize: Int32

Tamaño de la nueva matriz.

Excepciones

ArgumentOutOfRangeException

newSize es menor que cero.

Ejemplos

En el ejemplo siguiente se muestra cómo afecta el cambio de tamaño a la matriz.

using namespace System;
static void PrintIndexAndValues(array<String^>^myArr)
{
    for(int i = 0; i < myArr->Length; i++)
    {
       Console::WriteLine(L"   [{0}] : {1}", i, myArr[i]);
    }
    Console::WriteLine();
}

int main()
{
   
    // Create and initialize a new string array.
    array<String^>^myArr = {L"The", L"quick", L"brown", L"fox",
        L"jumps", L"over", L"the", L"lazy", L"dog"};
   
    // Display the values of the array.
    Console::WriteLine( 
        L"The string array initially contains the following values:");
    PrintIndexAndValues(myArr);
   
    // Resize the array to a bigger size (five elements larger).
    Array::Resize(myArr, myArr->Length + 5);
   
    // Display the values of the array.
    Console::WriteLine(L"After resizing to a larger size, ");
    Console::WriteLine(L"the string array contains the following values:");
    PrintIndexAndValues(myArr);
   
    // Resize the array to a smaller size (four elements).
    Array::Resize(myArr, 4);
   
    // Display the values of the array.
    Console::WriteLine(L"After resizing to a smaller size, ");
    Console::WriteLine(L"the string array contains the following values:");
    PrintIndexAndValues(myArr);
    return 1;
}

/* 
This code produces the following output.

The string array initially contains the following values:
   [0] : The
   [1] : quick
   [2] : brown
   [3] : fox
   [4] : jumps
   [5] : over
   [6] : the
   [7] : lazy
   [8] : dog

After resizing to a larger size, 
the string array contains the following values:
   [0] : The
   [1] : quick
   [2] : brown
   [3] : fox
   [4] : jumps
   [5] : over
   [6] : the
   [7] : lazy
   [8] : dog
   [9] :
   [10] :
   [11] :
   [12] :
   [13] :

After resizing to a smaller size, 
the string array contains the following values:
   [0] : The
   [1] : quick
   [2] : brown
   [3] : fox

*/

using System;

public class SamplesArray
{
    public static void Main()  {

        // Create and initialize a new string array.
        String[] myArr = {"The", "quick", "brown", "fox", "jumps",
            "over", "the", "lazy", "dog"};

        // Display the values of the array.
        Console.WriteLine(
            "The string array initially contains the following values:");
        PrintIndexAndValues(myArr);

        // Resize the array to a bigger size (five elements larger).
        Array.Resize(ref myArr, myArr.Length + 5);

        // Display the values of the array.
        Console.WriteLine("After resizing to a larger size, ");
        Console.WriteLine("the string array contains the following values:");
        PrintIndexAndValues(myArr);

        // Resize the array to a smaller size (four elements).
        Array.Resize(ref myArr, 4);

        // Display the values of the array.
        Console.WriteLine("After resizing to a smaller size, ");
        Console.WriteLine("the string array contains the following values:");
        PrintIndexAndValues(myArr);
    }

    public static void PrintIndexAndValues(String[] myArr)  {
        for(int i = 0; i < myArr.Length; i++)
        {
            Console.WriteLine("   [{0}] : {1}", i, myArr[i]);
        }
        Console.WriteLine();
    }
}

/*
This code produces the following output.

The string array initially contains the following values:
   [0] : The
   [1] : quick
   [2] : brown
   [3] : fox
   [4] : jumps
   [5] : over
   [6] : the
   [7] : lazy
   [8] : dog

After resizing to a larger size,
the string array contains the following values:
   [0] : The
   [1] : quick
   [2] : brown
   [3] : fox
   [4] : jumps
   [5] : over
   [6] : the
   [7] : lazy
   [8] : dog
   [9] :
   [10] :
   [11] :
   [12] :
   [13] :

After resizing to a smaller size,
the string array contains the following values:
   [0] : The
   [1] : quick
   [2] : brown
   [3] : fox

*/

open System

let printIndexAndValues (myArr: string []) =
    for i = 0 to myArr.Length - 1 do
        printfn $"   [{i}] : {myArr[i]}"
    printfn ""

// Create and initialize a new string array.
let mutable myArr = 
    [| "The"; "quick"; "brown"; "fox"; "jumps"
       "over"; "the"; "lazy"; "dog" |]

// Display the values of the array.
printfn "The string array initially contains the following values:"
printIndexAndValues myArr

// Resize the array to a bigger size (five elements larger).
Array.Resize(&myArr, myArr.Length + 5)

// Display the values of the array.
printfn "After resizing to a larger size, "
printfn "the string array contains the following values:"
printIndexAndValues myArr

// Resize the array to a smaller size (four elements).
Array.Resize(&myArr, 4)

// Display the values of the array.
printfn "After resizing to a smaller size, "
printfn "the string array contains the following values:"
printIndexAndValues myArr


(*
This code produces the following output.

The string array initially contains the following values:
   [0] : The
   [1] : quick
   [2] : brown
   [3] : fox
   [4] : jumps
   [5] : over
   [6] : the
   [7] : lazy
   [8] : dog

After resizing to a larger size,
the string array contains the following values:
   [0] : The
   [1] : quick
   [2] : brown
   [3] : fox
   [4] : jumps
   [5] : over
   [6] : the
   [7] : lazy
   [8] : dog
   [9] :
   [10] :
   [11] :
   [12] :
   [13] :

After resizing to a smaller size,
the string array contains the following values:
   [0] : The
   [1] : quick
   [2] : brown
   [3] : fox

*)

Public Class SamplesArray

    Public Shared Sub Main()

        ' Create and initialize a new string array.
        Dim myArr As String() =  {"The", "quick", "brown", "fox", _
            "jumps", "over", "the", "lazy", "dog"}

        ' Display the values of the array.
        Console.WriteLine( _
            "The string array initially contains the following values:")
        PrintIndexAndValues(myArr)

        ' Resize the array to a bigger size (five elements larger).
        Array.Resize(myArr, myArr.Length + 5)

        ' Display the values of the array.
        Console.WriteLine("After resizing to a larger size, ")
        Console.WriteLine("the string array contains the following values:")
        PrintIndexAndValues(myArr)

        ' Resize the array to a smaller size (four elements).
        Array.Resize(myArr, 4)

        ' Display the values of the array.
        Console.WriteLine("After resizing to a smaller size, ")
        Console.WriteLine("the string array contains the following values:")
        PrintIndexAndValues(myArr)

    End Sub

    Public Shared Sub PrintIndexAndValues(myArr() As String)
        Dim i As Integer
        For i = 0 To myArr.Length - 1
            Console.WriteLine("   [{0}] : {1}", i, myArr(i))
        Next i
        Console.WriteLine()
    End Sub

End Class

'This code produces the following output.
'
'The string array initially contains the following values:
'   [0] : The
'   [1] : quick
'   [2] : brown
'   [3] : fox
'   [4] : jumps
'   [5] : over
'   [6] : the
'   [7] : lazy
'   [8] : dog
'
'After resizing to a larger size, 
'the string array contains the following values:
'   [0] : The
'   [1] : quick
'   [2] : brown
'   [3] : fox
'   [4] : jumps
'   [5] : over
'   [6] : the
'   [7] : lazy
'   [8] : dog
'   [9] :
'   [10] :
'   [11] :
'   [12] :
'   [13] :
'
'After resizing to a smaller size, 
'the string array contains the following values:
'   [0] : The
'   [1] : quick
'   [2] : brown
'   [3] : fox

Comentarios

Este método asigna una nueva matriz con el tamaño especificado, copia elementos de la matriz antigua a la nueva y, a continuación, reemplaza la matriz antigua por la nueva. array debe ser una matriz unidimensional.

Si array es null, este método crea una nueva matriz con el tamaño especificado.

Si newSize es mayor que el Length de la matriz antigua, se asigna una nueva matriz y todos los elementos se copian de la matriz antigua a la nueva. Si newSize es menor que el de la Length matriz antigua, se asigna una nueva matriz y los elementos se copian de la matriz antigua a la nueva hasta que se rellena el nuevo; el resto de los elementos de la matriz antigua se omiten. Si newSize es igual al de la Length matriz antigua, este método no hace nada.

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

El Resize método solo cambia el tamaño de una matriz unidimensional. La Array clase no incluye un método para cambiar el tamaño de matrices multidimensionales. Para ello, debe proporcionar su propio código o llamar a un método de propósito especial en una biblioteca de terceros. En el código siguiente se muestra una posible implementación de un método que cambia el tamaño de una matriz de n dimensiones.

using System;

public class Example
{
   public static void Main()
   {
      int[,] arr = new int[10,2];
      for (int n1 = 0; n1 <= arr.GetUpperBound(0); n1++) {
         arr[n1, 0] = n1;
         arr[n1, 1] = n1 * 2;
      }

      // Make a 2-D array larger in the first dimension.
      arr = (int[,]) ResizeArray(arr, new int[] { 12, 2} );
      for (int ctr = 0; ctr <= arr.GetUpperBound(0); ctr++)
         Console.WriteLine("{0}: {1}, {2}", ctr, arr[ctr, 0], arr[ctr, 1]);
      Console.WriteLine();

      // Make a 2-D array smaller in the first dimension.
      arr = (int[,]) ResizeArray(arr, new int[] { 2, 2} );
      for (int ctr = 0; ctr <= arr.GetUpperBound(0); ctr++)
         Console.WriteLine("{0}: {1}, {2}", ctr, arr[ctr, 0], arr[ctr, 1]);
   }

   private static Array ResizeArray(Array arr, int[] newSizes)
   {
      if (newSizes.Length != arr.Rank)
         throw new ArgumentException("arr must have the same number of dimensions " +
                                     "as there are elements in newSizes", "newSizes");

      var temp = Array.CreateInstance(arr.GetType().GetElementType(), newSizes);
      int length = arr.Length <= temp.Length ? arr.Length : temp.Length;
      Array.ConstrainedCopy(arr, 0, temp, 0, length);
      return temp;
   }
}
// The example displays the following output:
//       0: 0, 0
//       1: 1, 2
//       2: 2, 4
//       3: 3, 6
//       4: 4, 8
//       5: 5, 10
//       6: 6, 12
//       7: 7, 14
//       8: 8, 16
//       9: 9, 18
//       10: 0, 0
//       11: 0, 0
//
//       0: 0, 0
//       1: 1, 2

open System

let resizeArray (arr: Array) (newSizes: int []) =
    if newSizes.Length <> arr.Rank then
        invalidArg "newSizes" "arr must have the same number of dimensions as there are elements in newSizes"
    let temp = Array.CreateInstance(arr.GetType().GetElementType(), newSizes)
    let length = min arr.Length temp.Length
    Array.ConstrainedCopy(arr, 0, temp, 0, length)
    temp

[<EntryPoint>]
let main _ =
    let arr = Array2D.init 10 2 (fun x y -> if y = 0 then x else x * 2)

    // Make a 2-D array larger in the first dimension.
    let arr = resizeArray arr [| 12; 2 |]
    for i = 0 to arr.GetUpperBound 0 do
        printfn $"{i}: {arr.GetValue(i, 0)}, {arr.GetValue(i, 1)}"
    printfn ""

    // Make a 2-D array smaller in the first dimension.
    let arr = resizeArray arr [| 2; 2|]
    for i = 0 to arr.GetUpperBound 0 do
        printfn $"{i}: {arr.GetValue(i, 0)}, {arr.GetValue(i, 1)}"
    0

// The example displays the following output:
//       0: 0, 0
//       1: 1, 2
//       2: 2, 4
//       3: 3, 6
//       4: 4, 8
//       5: 5, 10
//       6: 6, 12
//       7: 7, 14
//       8: 8, 16
//       9: 9, 18
//       10: 0, 0
//       11: 0, 0
//
//       0: 0, 0
//       1: 1, 2

Module Example
   Public Sub Main()
      Dim arr(9, 1) As Integer
      For n1 As Integer = 0 To arr.GetUpperBound(0)
         arr(n1, 0) = n1
         arr(n1, 1) = n1 * 2
      Next 

      ' Make a 2-D array larger in the first dimension.
      arr = CType(ResizeArray(arr, { 12, 2} ), Integer(,))
      For ctr = 0 To arr.GetUpperBound(0)
         Console.WriteLine("{0}: {1}, {2}", ctr, arr(ctr, 0), arr(ctr, 1))
      Next
      Console.WriteLine()
      
      ' Make a 2-D array smaller in the first dimension.
      arr = CType(ResizeArray(arr, { 2, 2} ), Integer(,))
      For ctr = 0 To arr.GetUpperBound(0)
         Console.WriteLine("{0}: {1}, {2}", ctr, arr(ctr, 0), arr(ctr, 1))
      Next
   End Sub

   Private Function ResizeArray(arr As Array, newSizes() As Integer) As Array
      If newSizes.Length <> arr.Rank Then
         Throw New ArgumentException("arr must have the same number of dimensions " +
                                     "as there are elements in newSizes", "newSizes") 
      End If 

      Dim temp As Array = Array.CreateInstance(arr.GetType().GetElementType(), newSizes)
      Dim length As Integer = If(arr.Length <= temp.Length, arr.Length, temp.Length )
      Array.ConstrainedCopy(arr, 0, temp, 0, length)
      Return temp
   End Function
End Module
' The example displays the following output:
'       0: 0, 0
'       1: 1, 2
'       2: 2, 4
'       3: 3, 6
'       4: 4, 8
'       5: 5, 10
'       6: 6, 12
'       7: 7, 14
'       8: 8, 16
'       9: 9, 18
'       10: 0, 0
'       11: 0, 0
'       
'       0: 0, 0
'       1: 1, 2

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