IntPtr.Add Method

The Add method does not throw an exception if the result is too large to represent as a pointer on the specified platform. Instead, the addition operation is performed in an unchecked context.

Languages that do not support operator overloading or custom operators can use this method to add an offset to the value of a pointer.

The following example instantiates an IntPtr object that points to the beginning of a ten-element array, and then calls the Add method to iterate the elements in the array.

using System;
using System.Runtime.InteropServices;

public class Example
{
   public static void Main()
   {
      int[] arr = { 2, 4, 6, 8, 10, 12, 14, 16, 18, 20 };
      unsafe {
         fixed(int* parr = arr) {
            IntPtr ptr = new IntPtr(parr);   
            for (int ctr = 0; ctr < arr.Length; ctr++)
            {
               IntPtr newPtr = IntPtr.Add(ptr, ctr * sizeof(Int32));
               Console.Write("{0}   ", Marshal.ReadInt32(newPtr));
            }
         }      
      }
   }
}
// The example displays the following output:
//       2   4   6   8   10   12   14   16   18   20

.NET Framework

.NET Framework Client Profile

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference