procedure _val_arr_set(var Item:TData; var Val:TData);
     function _val_arr_get(Var Item:TData; var Val:TData):boolean;
     function _val_arr_count:integer;
//...
    procedure _var_ValueArray(var _Data:TData; Index:word);

procedure THIListBox._val_arr_set;
var ind:integer;
begin
   ind := ToIntIndex(Item);
   if(ind >=0 )and(ind < Control.Count)then
    Control.Perform(LB_SETITEMDATA, ind, ReadInteger(Val, NULL, 0));
end;

function THIListBox._val_arr_get;
var ind:integer;
begin
   ind := ToIntIndex(Item);
   Result := (ind >=0 )and(ind < Control.Count);
   if Result then
     dtInteger(Val,integer(Control.Perform(LB_GETITEMDATA, ind, 0)));
end;

function THIListBox._val_arr_count;
var i:smallint;
begin
   Result := Control.Count;
end;

procedure THIListBox._var_ValueArray;
begin
  if ValArr = nil then
    ValArr := CreateArray(_val_arr_set,_val_arr_get,_val_arr_count,nil);
  dtArray(_Data,ValArr);
end;