德尔福 – 检测同时按下3个键

procedure TForm1.FormKeyDown(Sender: TObject; var Key: Word;
  Shift: TShiftStatE);
begin
  if Shift = [ssCtrl] then begin
    case Key of
      Ord('C'):
        if (GetKeyState(Ord('N')) and $80) = $80 then
          Showmessage('combo');
      Ord('N'):
        if (GetKeyState(Ord('C')) and $80) = $80 then
          Showmessage('combo');
    end;
  end;
end;

但是,这也将检测例如N Ctrl C,这是一个不以Ctrl键开头的序列.如果这不符合有效的密钥组合,您可以借助标记保留一些密钥历史记录.以下应仅检测最初以Ctrl开头的序列：

type
  TForm1 = class(TForm)
    procedure FormKeyDown(Sender: TObject; var Key: Word; Shift: TShiftStatE);
    procedure FormKeyUp(Sender: TObject; var Key: Word; Shift: TShiftStatE);
  private
    FValidKeyCombo: Boolean;
  end;

...

procedure TForm1.FormKeyDown(Sender: TObject; var Key: Word;
  Shift: TShiftStatE);
begin
  if FValidKeyCombo and (Shift = [ssCtrl]) then
    case Key of
      Ord('C'):
        if (GetKeyState(Ord('N')) and $80) = $80 then
          Showmessage('combo');
      Ord('N'):
        if (GetKeyState(Ord('C')) and $80) = $80 then
          Showmessage('combo');
    end;
  FValidKeyCombo := (Shift = [ssCtrl]) and (Key in [Ord('C'),Ord('N')]);
end;

procedure TForm1.FormKeyUp(Sender: TObject; var Key: Word; Shift: TShiftStatE);
begin
  FValidKeyCombo := false;
end;