procedure TFRMXSDD.DataGridZSLDrawSummaryFooter(Sender: TObject; ACanvas: TCanvas; ARect: TRect; var AText: string; var AAlignment: TAlignment; AFont: TFont; var AColor: Integer; var ADone: Boolean);
var
i:integer;
s:string;
f:float;
begin
f:=0;
for i:=0 to DataGrid.Count-1 do
begin
s:=DataGrid.Items.Strings[6];
if SysUtils.Trim(s)='' then
s:='0';
f:=f+SysUtils.StrToFloat(s);
end;
AText :=SysUtils.FloatToStr(f);
end;