？怎么让鼠标在DBGrid内部不同列移动时，显示当前单元格Hint值？

type
 TMyGrid = Class(TCustomDBGrid);

procedure TForm1.DBGrid1MouseMove(Sender: TObject; Shift: TShiftState; X,
  Y: Integer);
var
  row, col : integer;
  rec : integer;
begin
  inherited;

  TDBGrid(Sender).MouseToCell(X, Y, col, row);

  if dgTitles in TDBGrid(Sender).Options then
    Dec(row);
  if dgIndicator in TDBGrid(Sender).Options then
    Dec(col);

  if TMyGrid(TDBGrid(Sender)).DataLink.Active and
     (row >= 0) and (col >= 0) then begin
    rec := TMyGrid(TDBGrid(Sender)).DataLink.ActiveRecord;
    try
      TMyGrid(TDBGrid(Sender)).DataLink.ActiveRecord := row;
      TDBGrid(Sender).Hint := 'Content of field : '+
                              TDBGrid(Sender).Columns[col].Field.AsString;
      Application.ActivateHint(Mouse.CursorPos);
    finally
      TMyGrid(TDBGrid(Sender)).DataLink.ActiveRecord:= rec;
    end;
  end;
end;