public string UpdateCartProductQuantity() { int productId = -1; String productColor = ""; String productSize = ""; int quantity = -1; MemoryStream stream = new MemoryStream(); Request.Body.CopyTo(stream); stream.Position = 0; using (StreamReader reader = new StreamReader(stream)) { string requestBody = reader.ReadToEnd(); if (requestBody.Length > 0) { var obj = JsonConvert.DeserializeObject <PostData>(requestBody); if (obj != null) { productId = int.Parse(obj.productId); productColor = obj.productColor; productSize = obj.productSize; quantity = int.Parse(obj.quantity); } } } double newPrice = CartProductManager.updateCartProductQuantity(productId, productColor, productSize, quantity); return(newPrice + "-" + CartProductManager.getTotalPrice()); }