DBGridEh checkbox的一个问题

function TCustomDBGridEh.CheckBeginRowMoving(MouseX, MouseY: Integer; CheckInOnly: Boolean): Boolean;
var
  Cell: TGridCoord;
  Bookmark: TUniBookmarkEh;
  DataRow: Integer;
begin
  Result := False;
  if not DataLink.Active or not (dghRecordMoving in OptionsEh) then Exit;
  Cell := MouseCoord(MouseX, MouseY);
  Result := (Cell.X >= 0) and (Cell.X < FIndicatorOffset) and
    (Cell.Y > TopDataOffset - 1) and (Cell.Y < RowCount) and
    DataLink.Active and not (DataSource.DataSet.Eof and DataSource.DataSet.Bof);
  if Result then
  begin
    DataRow := Cell.Y - TopDataOffset;
    InstantReadRecordEnter(DataRow);
    try
      Bookmark := DataLink.DataSet.Bookmark;
      FMoveRowSourLevel := -1;
      if MemTableSupport then
        FMoveRowSourLevel := FIntMemTable.GetTreeNodeLevel;
      if CanSelectType(gstRecordBookmarks) then
        Result := FBookmarks.CurrentRowSelected and (GetShiftState * [ssShift, ssAlt, ssCtrl] = []);

 把GetShiftState * [ssShift, ssAlt, ssCtrl]取消。