///////Begin Source
function GetDBGridEdit(mDBGrid: TDBGrid): TEdit;
var
  I: Integer;
begin
  Result := nil;
  if not Assigned(mDBGrid) then Exit;
  if not mDBGrid.EditorMode then begin
    mDBGrid.EditorMode := True;
    mDBGrid.EditorMode := False;
  end;
  with mDBGrid do for I := 0 to PRed(ComponentCount) do
    if Components[I] is TCustomEdit then begin
      Result := TEdit(Components[I]);
      Break;
    end;
end; { GetDBGridEdit }

function GetDBGridEditText(mDBGrid: TDBGrid): string;
var
  vEdit: TEdit;
begin
  vEdit := GetDBGridEdit(mDBGrid);
  if Assigned(vEdit) then
    Result := vEdit.Text
  else Result := '';
end; { GetDBGridEditText }
///////End Source

///////Begin Demo
procedure TForm1.DBGrid1Enter(Sender: TObject);
var
  vEdit: TEdit;
begin
  vEdit := GetDBGridEdit(TDBGrid(Sender));
  if Assigned(vEdit) then vEdit.Color := clYellow;
end;

procedure TForm1.DBGrid1KeyUp(Sender: TObject; var Key: Word;
  Shift: TShiftState);
begin
  Caption := GetDBGridEditText(TDBGrid(Sender));
end;
///////End Demo