public IActionResult ChangeQuantity(int sellerId, int productTypeId, bool isAdd, short number = 0) { if (loginPersistence.PersistLogin() == null) { return(Json("Not login")); } try { ICollection <string> errors; if (isAdd) { eCommerce.AddProductQuantityThroughAdmin(sellerId, productTypeId, number, out errors); } else { eCommerce.ReduceProductQuantityThroughAdmin(sellerId, productTypeId, number, out errors); } if (errors.Any()) { string errorString = ""; foreach (string error in errors) { errorString += error + "\n"; } errorString.Remove(errorString.Length - 1); return(Json(errorString)); } } catch (Exception e) { return(Json(e.Message)); } return(Json("")); }