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Avatar of _sunny_
_sunny_

Strange problem with catching Alt-F6 key on WM_KEYDOWN/WM_SYSKEYDOWN
That is the problem.
New application (Project1.dpr).
In my own message loop (PeekMessage/DispatchMessage) I can intercept all keys except the F6 when Alt is holded. WHY????????????

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Avatar of TOndrejTOndrej

could you perhaps show the code
Avatar of _sunny__sunny_

ASKER

procedure TForm1.Button1Click(Sender: TObject);
var
  M : TMsg;
begin
  while True do
    begin
      if PeekMessage(M, 0, 0, 0, PM_REMOVE) then
      begin
        if (M.Message = WM_KEYDOWN) or (M.Message = WM_SYSKEYDOWN) then
          // OutputDebugString do not outs any string about F6, but shows
          // F1, F2, F3 etc...
          OutputDebugString(PChar(IntToStr(M.hwnd) + ' ' +
                                  IntToStr(M.message) + ' '+
                                  IntToStr(M.wParam)));
        DispatchMessage(M)
      end
      else
        WaitMessage;
    end;
end;
Avatar of LischkeLischke

I bet there is a program which has registered Alt+F6 as hotkey. If this is the case you cannot do anything about it...

Ciao, Mike
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Avatar of _sunny__sunny_

ASKER

:)
Avatar of LischkeLischke

Just smiling? No comment? :-)
Avatar of _sunny__sunny_

ASKER

What API function you mean when talking about "Hot Key"? What do you mean when saying "registered Alt+F6 as hotkey"???
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Avatar of LischkeLischke

The API is RegisterHotKey
Avatar of _sunny__sunny_

ASKER

 Randomize;
  if not RegisterHotKey(Handle,
           GlobalAddAtom(PChar('SunnyAtom' + IntToStr(Random(50000)))),
           MOD_ALT, VK_F6) then
    RaiseLastWin32Error;

// It shows no error
Avatar of arkamaxarkamax

I wasn't even able to show any F-key with Alt down, since it showed me repeated Alt WM_KEYDOWNs. Why do you need such a strange key catcher? It'd be much easier and better to override TForm1.WndProc and get the same with much less hassle. Regards, Artyom.
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Avatar of _sunny__sunny_

ASKER

If you answering, try your idea  at least before. RTFM, at last!
Avatar of arkamaxarkamax

Could you please just let me know what's wrong about overriding WndProc? For now it's not that clear what you try to achieve by using custom message loop, and therefore I suggested a TESTED documented technique (this is for RTFM). Regards, Artyom.
Avatar of _sunny__sunny_

ASKER

Did you try to intercept WM_KEYDOWN in TForm1.WndProc ? Succeded? Why? Because an active control's WndProc takes the message. Not form. KeyPreview := True? Try it... with same result.
What I try to achieve? Oh... it is a long story. I have a small application (about 2 milion lines), I make its transition to Windows from DOS. So I have something like KeyPressed/ReadKey emulator inside. Of course it is a windows message loop.

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Avatar of _sunny__sunny_

ASKER

Adjusted points from 200 to 500
Avatar of PLCPLC

No solution for you, but I found it strange enough to try it myself and it gives indeed the result you mentionned.
If I assign that key to a menu option, no reaction.
I tried to register the alt-f6 as hotkey which my machine allows me to do, but the key doesn't work.
It would surprise me if we have the same program running that registers that key except for windows itself probably.
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Avatar of _sunny__sunny_

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Comment accepted as answer
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Avatar of _sunny__sunny_

ASKER

Cool, but it looks we still have a problem :(
Avatar of LischkeLischke

Oh, thank you _sunny_. Didn't expect to get the points :-)

I'm sure with some extremly high effort you could catch system keys too, but you would need to capture them before the system gets them. Hence it would something like a keyboard driver. Not a very elegant solution, however :-(

Ciao, Mike
Avatar of _sunny__sunny_

ASKER

Oh, no! :)
I think users of previous versions will take some efforts to get into habit Alt+F8 key instead :)

Thank you.
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