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hookpower-managementwindows-messages

How to detect Windows suspend message?

Does somebody know how to detect a Windows suspend message by C/C++ code?

Or, does SetWindowsHookEx() function do this?

Does somebody have these code for me? I want to detect this message.

Solution

  • If you are talking about sleep and hibernate – the answer is yes, you can. You just need to listen to WM_POWERBROADCAST message.

    Suppose you have an MFC application and a window class which is a subclass of CWnd. Then you can do:

    BEGIN_MESSAGE_MAP(CMyWindow, CWnd)
    //{{AFX_MSG_MAP(CMyWindow)
    ON_MESSAGE(WM_POWERBROADCAST, OnMsgPowerBroadcast)
    //}}AFX_MSG_MAP
END_MESSAGE_MAP()

...

LRESULT CMyWindow::OnMsgPowerBroadcast(WPARAM wParam, LPARAM lParam)
{
    if (wParam == PBT_APMSUSPEND) {
        // The system is suspending.
    }
    return TRUE; 
}