Get Notified about Windows is Going to Sleep/Waking up in C++ - c++

Question

I am working on an App which has Multiple Threads waiting for different inputs from DLLs and Serial Ports.
I want to add a functionality that before machine going to Sleep, I have to unload certain DLL and On waking up have to Re-load the DLL.
For this, I need to get notified on Sleep and Wake up.
I found many files about doing in C# but I want to do this in C++.
I tried using this code Project but could not capture any event. I removed everything related to Window Paint and All that as I do not need it's GUI and kept only main message loop (The While loop in the main)
EDIT:-
I am using this as my main loop:-
// Start the message loop.
while( (bRet = GetMessage( &msg, NULL, 0, 0 )) != 0)
{
if (bRet == -1)
{
// handle the error and possibly exit
}
else
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
}
To be frank I have copied this from CodeProject, and Made only one Modification i.e. Checked GetMessage(..) != 0 from a MSDN Article.
Am I missing something?
Or anyother Solution??
I am using VS2010 and programming in C++
Thanks in Advance!

Answer 1

Try handling the WM_POWERBROADCAST message
Here's sample code that should work. Apparently you do need to create a window otherwise you don't receive the messages. The sample creates a hidden window to achieve this.
static long FAR PASCAL WindowProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
if(message == WM_POWERBROADCAST)
{
//Do something
return TRUE;
}
else
return DefWindowProc(hWnd, message, wParam, lParam);
}
int _tmain(int argc, _TCHAR* argv[])
{
WNDCLASS wc = {0};
// Set up and register window class
wc.lpfnWndProc = WindowProc;
wc.lpszClassName = _T("SomeNameYouInvented");
RegisterClass(&wc);
HWND hWin = CreateWindow(_T("SomeNameYouInvented"), _T(""), 0, 0, 0, 0, 0, NULL, NULL, NULL, 0);
BOOL bRet;
MSG msg;
while( (bRet = GetMessage( &msg, hWin, 0, 0 )) != 0)
{
if (bRet == -1)
{
// handle the error and possibly exit
}
else
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
}
return 0;
}