Очередь обработчиков сообщения

function FrameListGetMsgHookHandler(CODE, WParam, LParam: DWORD): DWORD; stdcall;
var
  _msg:PMsg;
begin
    Result:=CallNextHookEx(GGetMsgHookHandle, CODE, WParam, LParam);
    if CODE=HC_ACTION then
    begin
        _msg:=PMsg(LParam);
        if (_msg^.message=WM_MOUSEWHEEL) then begin
            if (GGetMsgHookMsgDest<>0) then begin
                SendMessage(GGetMsgHookMsgDest, WM_CUSTOM_MOUSE_Wheel2, WParam, LParam);
            end;
        end;
    end;
end;

WM_CUSTOM_MOUSE_Wheel2: begin
        if (csDesigning in ComponentState) then exit;
 
         msg1:=PMsg(Msg.LParam);
         if msg1.hwnd<>FListPanel.Handle then begin
            if (MouseIn(FListPanel) or MouseIn(Fscroller)) then
            WI.cbSize:=sizeof(tagwindowinfo);
                GetWindowInfo(msg1.hwnd,WI);
                GetClassName(msg1.hwnd, WinClass, SizeOf(WinClass));
                //showmessage(WinClass);
         end;
    end;

procedure TForm1.ScrollBox1MouseWheel(Sender: TObject; Shift: TShiftState;
  WheelDelta: Integer; MousePos: TPoint; var Handled: Boolean);
begin
  if (ActiveControl = ScrollBox1) or not (PtInRect(ActiveControl.BoundsRect, ActiveControl.Parent.ScreenToClient(MousePos))) then
  begin
    ScrollBox1.VertScrollBar.Position := ScrollBox1.VertScrollBar.Position - WheelDelta div 6;
    Handled := True;
  end else
    if ActiveControl is TSpinEdit then
    begin
      (ActiveControl as TSpinEdit).Value := (ActiveControl as TSpinEdit).Value + WheelDelta div 120;
      Handled := True;
    end;
end;

procedure TForm1.FormKeyPress(Sender: TObject; var Key: Char);
begin
  if Key = #27 then
    ActiveControl := ScrollBox1;
end;