Copy HWND into shared memory buffer

[Opariti]

Hi experts!
I'm trying to use a memory shared (memory mapped files) mechanism to transmit a window handle (HWND type) from C to C#. I've successfully used it to transmit strings.
In the case of handle, I get a system run-time error (build is fine) at the shared memory buffer copy (CopyMemory) of the window's handle (I write below all associated code):

HWND parentHandle; // This is initialized elsewhere by creating a simple window
LPVOID pBuf;
....................
// Create the shared buffer (Memory Mapped File)
	hMapFile = CreateFileMapping(
                 INVALID_HANDLE_VALUE,    // use paging file
                 NULL,                    // default security 
                 PAGE_READWRITE,          // read/write access
                 0,                       // maximum object size (high-order DWORD) 
                 BUF_SIZE,                // maximum object size (low-order DWORD)  
                 szsharedBufferName);     // name of mapping object 
   if (hMapFile == NULL) 
   { 
	  DisplayLastError(L"Could not file mapping object");
      return 1;
   }

   // Create a view into the created shared buffer so that can read/write access it
   //pBuf = (LPTSTR) MapViewOfFile(hMapFile,   // handle to map object
   pBuf = MapViewOfFile(hMapFile,   // handle to map object
                        FILE_MAP_ALL_ACCESS, // read/write permission
                        0,                   
                        0,                   
                        BUF_SIZE);           
   if (pBuf == NULL) 
   { 
	   DisplayLastError(L"Could not map view of file");
	   CloseHandle(hMapFile);
       return 1;
   }

   // Write the handle into the shared buffer
      CopyMemory((PVOID) pBuf, parentHandle, 4);

The HWND's length is 4 bytes (tested also with sizeof(parentHandle)). The debugger (VS2010 Beta) brings me to the assembler code where a mov operation, inside CopyMemory, is corrupted.
For me, the HWND is a system number on 32 bits, associated to a system window object, so it should work.
Many thanks,
Opariti

[adeyblue]

// Write the handle into the shared buffer
CopyMemory((PVOID) pBuf, parentHandle, 4);

You forgot the &. You want the 4/8 bytes at the address of parentHandle, not the 4/8 bytes pointer to by parentHandle.
CopyMemory((PVOID) pBuf, &parentHandle, sizeof(parentHandle));

[Opariti]

Thanks, that's it, I've already tried with & and went on.
The explanation is clear!
Just in case, though out of the forum: do you know how could I pick up the handle as a IntPtr in C# (from a 4 element byte-array)?