lazarus DBGridEh标题栏排序

lazarus DBGridEh标题栏排序
按网上(delphi)的方法发现无效，经测试，以下代码可以正常排序：

unit Unit1;

{$mode ObjFPC}{$H+}

interface

uses
  Classes, SysUtils, DB, Forms, Controls, Graphics, Dialogs, StdCtrls, Uni,
  DBGridsEh, DBCtrlsEh, LConvEncoding, DBGridEhImpExp, lclintf, DBGrids,
  ToolCtrlsEh;

type

  { TForm1 }

  TForm1 = class(TForm)
    DataSource1: TDataSource;
    grdRateValue: TDBGridEh;
    UniConnection1: TUniConnection;
    UniQuery1: TUniQuery;
    procedure FormCreate(Sender: TObject);
    procedure grdRateValueTitleBtnClick(Sender: TObject; ACol: Integer;
      Column: TColumnEh);
  private

  public

  end;

var
  Form1: TForm1;

implementation

{$R *.lfm}

{ TForm1 }

procedure TForm1.FormCreate(Sender: TObject);
var i,j:integer;
begin
  if UniConnection1.Connected then UniConnection1.Connected:=False;
  UniConnection1.ProviderName:='SQLite';
  with UniConnection1 do
  begin
    Database:=ExtractFilePath(Application.ExeName)+'db';
    SpecificOptions.Values['ClientLibrary']:=UTF8ToCP936(ExtractFilePath(Application.ExeName))+'sqlite3_x64.dll';
    SpecificOptions.Values['useunicode']:='True';
    Connected:=True;
  end;
  if UniQuery1.Active then UniQuery1.Close;
  UniQuery1.SQL.Clear;
  UniQuery1.SQL.Add('select * from Ratevalue   order by rate  DESC');
  UniQuery1.Open;
  grdRateValue.OptionsEh:= [dghAutoSortMarking, dghMultiSortMarking];
  i:=grdRateValue.Columns.Count;
  for j:=0 to i-1 do
    grdRateValue.Columns[j].Title.TitleButton := True;
  grdRateValue.OnTitleBtnClick := @grdRateValueTitleBtnClick;
end;

procedure TForm1.grdRateValueTitleBtnClick(Sender: TObject; ACol: Integer;
  Column: TColumnEh);
begin
  UniQuery1.Close;
  UniQuery1.SQL.Clear;
  UniQuery1.DisableControls;
  grdRateValue.DataSource:=nil;
  if column.Title.SortMarker=smDownEh then
     UniQuery1.SQL.Text:='select * from Ratevalue   order by '+ column.FieldName +' ASC'
  else
     UniQuery1.SQL.Text:='select * from Ratevalue   order by '+ column.FieldName +' DESC';

  UniQuery1.Open;
  UniQuery1.EnableControls;
  form1.Caption:= UniQuery1.RecordCount.ToString;
  grdRateValue.DataSource:=Datasource1;
end;

end.