procedure TWinControl.WMKeyDown(var Message: TWMKeyDown);
begin
  if not DoKeyDown(Message) then inherited;
  UpdateUIState(Message.CharCode);
end;

function TWinControl.DoKeyDown(var Message: TWMKey): Boolean;
var
  ShiftState: TShiftState;
  Form, FormParent: TCustomForm;
  LCharCode: Word;
begin
  Result := True;
  { First give the immediate parent form a try at the Message }
  Form := GetParentForm(Self, False);
  if (Form <> nil) and (Form <> Self) then
  begin
    if Form.KeyPreview and TWinControl(Form).DoKeyDown(Message) then
      Exit;
    { If that didn't work, see if that Form has a parent (ie: it is docked) }
    if Form.Parent <> nil then
    begin
      FormParent := GetParentForm(Form);
      if (FormParent <> nil) and (FormParent <> Form) and
      FormParent.KeyPreview and TWinControl(FormParent).DoKeyDown(Message) then
        Exit;
    end;
  end;
  with Message do
  begin
    ShiftState := KeyDataToShiftState(KeyData);
    if not (csNoStdEvents in ControlStyle) then
    begin
      LCharCode := CharCode;
      KeyDown(LCharCode, ShiftState); //<---------------------------------
      CharCode := LCharCode;
      if LCharCode = 0 then Exit;
    end;
  end;
  Result := False;
end;

procedure TWinControl.KeyDown(var Key: Word; Shift: TShiftState);
begin
  if Assigned(FOnKeyDown) then FOnKeyDown(Self, Key, Shift);
end;