Drop Box Dinamis

...
type
  TString = class(TObject)
    private
      fStr: String;
    public
    constructor Create(const AStr: String) ;
    property Str: String read FStr write FStr;

...
constructor TString.Create(const AStr: String);
begin
  inherited Create;
  FStr := AStr;
end;


Proses ke combobox nya :
-------------------------------

cbDealer.Properties.Items.Clear;
  with DM.Q do
  begin
    Close;
    SQL.Text := 'select KD_DEALER,NAMA_DEALER from t_faktur'+
                ' where DATE_FORMAT(tgl_faktur, ''%Y%m%d'') between :tgl and :tgl2 group by KD_DEALER order by KD_DEALER';
    Params[0].AsString := FormatDateTime('yyyymmdd',dt.Date);
    Params[1].AsString := FormatDateTime('yyyymmdd',dt2.Date);
    Open;

    if DM.Q.RecordCount > 0 then
    begin
      while not eof do
      begin
        cbDealer.Properties.Items.AddObject(Fields[1].AsString,TString.Create(Fields[0].AsString));
      Next;
      end;
    end
    else
    begin
      cbDealer.Properties.Items.AddObject('SEMUA DEALER',TString.Create('ALL'));
    end;
  end;
 
  cbDealer.Text := '';

.......

Penggunaan pada saat combobox di pilih adalah sebagai berikut:

params() := TString(cbDealer.Properties.Items.Objects[cbDealer.ItemIndex]).Str;