[Casimiro Noteví]

Pues mejor copiarlo aqui

Código Delphi [-]
procedure TManFarmaQry.StringGrid1HeaderClick(Column: TColumn);
begin
  // Putting things practical    
  if mtblMedica.IndexFieldNames = LinkGridToDataSourceBindSourceDB1.Columns[Column.Index].MemberName then
    mtblMedica.IndexFieldNames := LinkGridToDataSourceBindSourceDB1.Columns[Column.Index].MemberName + ''
  else
    mtblMedica.IndexFieldNames := LinkGridToDataSourceBindSourceDB1.Columns[Column.Index].MemberName;

  // Here is the solution. Refresh datasource
  LinkGridToDataSourceBindSourceDB1.Active := False;
  LinkGridToDataSourceBindSourceDB1.Active := True;
end;