How can I get the process filename under Vista?

Question

I have an application that aids people with disabilities. In order to work, it tracks the what window is currently in the foreground. Normally, I use this function to get process executable.

bool GetWindowProcessExe2(HWND hwnd, wxString& process_exe)  
                       //LPTSTR buf, DWORD size)
{
DWORD result = 0;
DWORD pid = 0;
GetWindowThreadProcessId(hwnd, &pid);
if (HANDLE process =
    OpenProcess(PROCESS_ALL_ACCESS, FALSE, pid))
{
  char buff[512];
  LPTSTR pbuff = buff;
  result = GetModuleFileNameEx(process, 0, pbuff, 512);
  if(result == 0)
  {
    //failed.
    wxLogError("GetModuleFileNameEx failed with error code %d", GetLastError());
  }
  CloseHandle(process);
  process_exe = fromCString(pbuff);
}

return result > 0 ? true : false;

}

Unfortunately, if the foreground window is the Vista file manager window (the window that opens when you click Start->Computer), GetModuleFileNameEx() fails with error code 299 which says I don't have privileges for this action. My code works for any regular application but not for the windows built in window (the file explorer). I need to know when this window is forefront. Is there another way to do it? I tried reading the window title but that just returns the current directory being shown. Any ideas?

Answer 1

I'm not sure why this isn't working for explorer, but error 299 is ERROR_PARTIAL_COPY, meaning that attempting to read the module name out of explorer is failing.

On Vista, prefer QueryProcessImageFileName and only open the process with PROCESS_QUERY_LIMITED_INFORMATION - your code will work in more cases.

WCHAR exeName[512];
DWORD cchExeName = 512;
HANDLE process = OpenProcess(PROCESS_QUERY_LIMITED_INFORMATION, 0, pid);
QueryFullProcessImageName(process, 0, exeName, &cchExeName);

EDIT: I also got ERROR_PARTIAL_COPY with your code running on 64-bit, but only when the querying process was 32-bit. 64-bit/64-bit worked fine.