🚀 go-pugleaf

"Patryk B." <pbobak@no.spam.o2.pl> wrote in message 
news:op.t0140zizwzezly@dune.intranet...

> Im traying to prevent to close my application.
> I know its function OnCloseQuery but i want to
> prevent closing from Task Manager too.


Since your own app also sends WM_QUIT to itself, there is no direct way to 
know if WM_QUIT is coming from Task Manager or not.  So you can't just block 
WM_QUIT blindly, or else your app will never close at all.  At the very 
least, you will have to use the OnCloseQuery or OnClose event to set a flag 
that your WM_QUIT handler can check for.

Try this instead (untested):

    HHOOK hHook = NULL;
    bool bIsQuitting = false;

    LRESULT CALLBACK GetMsgProc(int nCode, WPARAM wParam, LPARAM lParam)
    {
        if( nCode == HC_ACTION )
        {
            PMSG msg = (PMSG) lParam;
            if( msg->message == WM_QUIT )
            {
                MessageBox(NULL, "WM_QUIT detected!", "GetMsgProc", MB_OK);
                if( !bIsQuitting )
                    msg->message = WM_NULL;
            }
        }

        return CallNextHookEx(hHook, nCode, wParam, lParam);
    }


    __fastcall TMainForm::TMainForm(TComponent *Owner)
        : TForm(Owner)
    {
        hHook = SetWindowsHookEx(WH_GETMESSAGE, (HOOKPROC) &GetMsgProc, 
NULL, MainThreadID);
        if( !hHook )
            ShowMessage("Couldnt set hook");
    }

    __fastcall TMainForm::~TMainForm()
    {
        if( hHook )
        {
            UnhookWindowsHookEx(hHook);
            hHook = NULL;
        }
    }

    void __fastcall TMainForm::FormCloseQuery(TObject *Sender, bool 
&CanClose)
    {
        if( some condition )
            CanClose = false;
    }

    void __fastcall TMainForm::FormClose(TObject *Sender, TCloseAction 
&Action)
    {
        bIsQuitting = true;
    }


Gambit