屏蔽组合键[Ctrl+N]

……

const
  _KeyPressMask=$80000000;

implementation

……

procedure TForm1.ApplicationEvents1Message(var Msg: tagMSG;
  var Handled: Boolean);
begin
  if ((Msg.lParam and _KeyPressMask)=0) and (GetKeyState(vk_control)<0) and (Msg.wParam = Ord('N')) then
    begin
    Handled := True;
    end;
end;

……