Question

in C#, is there a way to

1. Get the memory address stored in a reference type variable?
2. Get the memory address of a variable?

EDIT:

int i; int* pi = &i; 

• How do you print out the hex value of pi?

Answer 1

For #2, the & operator will work in the same fashion as in C. If the variable is not on the stack, you may need to use a fixed statement to pin it down while you work so the garbage collector does not move it, though.

For #1, reference types are trickier: you’ll need to use a GCHandle, and the reference type has to be blittable, i.e. have a defined memory layout and be bitwise copyable.

In order to access the address as a number, you can cast from pointer type to IntPtr (an integer type defined to be the same size as a pointer), and from there to uint or ulong (depending on the pointer size of the underlying machine).

using System; using System.Runtime.InteropServices;  [StructLayout(LayoutKind.Sequential)] class Blittable {     int x; }  class Program {     public static unsafe void Main()     {         int i;         object o = new Blittable();         int* ptr = &i;         IntPtr addr = (IntPtr)ptr;          Console.WriteLine(addr.ToString('x'));          GCHandle h = GCHandle.Alloc(o, GCHandleType.Pinned);         addr = h.AddrOfPinnedObject();         Console.WriteLine(addr.ToString('x'));          h.Free();     } }