IntPtr.Subtraction(IntPtr, Int32) Operador

Definición

Resta un desplazamiento del valor de un puntero.Subtracts an offset from the value of a pointer.

public:
 static IntPtr operator -(IntPtr pointer, int offset);
public static IntPtr operator - (IntPtr pointer, int offset);
static member ( - ) : nativeint * int -> nativeint
Public Shared Operator - (pointer As IntPtr, offset As Integer) As IntPtr

Parámetros

pointer
IntPtr

Puntero del que se va a restar el desplazamiento.The pointer to subtract the offset from.

offset
Int32

Desplazamiento que se va a restar.The offset to subtract.

Devoluciones

IntPtr

Nuevo puntero que es el resultado de restar offset de pointer.A new pointer that reflects the subtraction of offset from pointer.

Comentarios

El Subtraction método define la operación de resta de IntPtr objetos.The Subtraction method defines the subtraction operation for IntPtr objects. Permite el código como el siguiente.It enables code such as the following.

int[] arr = { 2, 4, 6, 8, 10, 12, 14, 16, 18, 20};
unsafe {
   fixed(int* parr = &arr[arr.GetUpperBound(0)])
   {
      IntPtr ptr = new IntPtr(parr);
      for (int ctr = 0; ctr <= arr.GetUpperBound(0); ctr++)
      {
         IntPtr newPtr = ptr - ctr * sizeof(Int32);
         Console.Write("{0}   ", Marshal.ReadInt32(newPtr));
      }
   }
}
// The example displays the following output:
//       20   18   16   14   12   10   8   6   4   2
Dim arr() As Integer = {2, 4, 6, 8, 10, 12, 14, 16, 18, 20 }
Dim ptr As IntPtr = Marshal.UnsafeAddrOfPinnedArrayElement(arr, arr.GetUpperBound(0))
For ctr As Integer= 0 To arr.GetUpperBound(0)
   Dim newPtr As IntPtr = ptr - ctr * Len(arr(0))
   Console.Write("{0}   ", Marshal.ReadInt32(newPtr))
Next

Los lenguajes que no admiten operadores personalizados pueden llamar al Subtract método en su lugar.Languages that do not support custom operators can call the Subtract method instead.

La operación de resta no inicia una excepción si el resultado es demasiado pequeño para representarse como un puntero en la plataforma especificada.The subtraction operation does not throw an exception if the result is too small to represent as a pointer on the specified platform. En su lugar, se realiza en un contexto no comprobado.Instead, it is performed in an unchecked context.

El método equivalente para este operador es IntPtr.Subtract(IntPtr, Int32)The equivalent method for this operator is IntPtr.Subtract(IntPtr, Int32)

Se aplica a

Consulte también