默认样式

procedure TIWForm1.IWDBGrid1HTMLTag(ASender: TObject; ATag: TIWHTMLTag);
begin
  ATag.AddStringParam('style'
  , 'table{margin:0 auto;border:1px solid #000000;border-collapse:collapse;}th,td{border: 1px solid #000000;text-align:center;} }'
   );
end;