Process.MainWindowHandle question

[Michiel]

Hello,

When I execute the following code

Process* oProc;
IntPtr ipMain;
HWND hWnd;
oProc=Process::GetProcessById(m_IProcId);
ipMain=oProc->MainWindowHandle;
hWnd=(HWND)ipMain.ToPointer();

if(bEnable){ ShowWindow(hWnd, SW_SHOWNORMAL) }
else { ShowWindow(hWnd, SW_HIDE) }

Inside a thread that runs alongside the desired process (m_IProcId) it works
_fine_ the first time, that is when I call the SW_HIDE. When I then want to
reactivate this window when the thread ends, I get the _correct_ processId,
the process is still running (wmplayer.exe), but it says the window handle
(hWnd) is invalid ? How is this possible ?

Thanks in advance !