通过alamofire将付款金额从ios前端发布到条带后端

因此，基本上我添加了一些功能，允许我向后端发布请求，以创建条带支付意图，并验证和运行该功能。到目前为止，当我将后端ruby文件中的amount值硬编码为一个设置值时，一切都正常。例如，如果我将金额硬编码为1099（10.99），则请求有效，并通过我的stripe sandbox通过10.99收费；但是，我想将我自己的金额值发布到后端以收取费用。下面是我试图编辑的stripe的posting方法的后端代码示例。在这里，我写amount=payload[:sub]，我过去有一个硬编码的amount值，所以它过去是amount=1099

post '/create_payment_intent' do
  authenticate!
  payload = params

  if request.content_type != nil and request.content_type.include? 'application/json' and params.empty?
      payload = Sinatra::IndifferentHash[JSON.parse(request.body.read)]
  end

  # Calculate how much to charge the customer
  amount = payload[:sub].to_f // This used to be - amount = 1099

  begin
    payment_intent = Stripe::PaymentIntent.create(
      :amount => amount,
      :currency => currency_for_country(payload[:country]),
      :customer => payload[:customer_id] || @customer.id,
      :description => "Example PaymentIntent",
      :capture_method => ENV['CAPTURE_METHOD'] == "manual" ? "manual" : "automatic",
      payment_method_types: payment_methods_for_country(payload[:country]),
      :metadata => {
        :order_id => '5278735C-1F40-407D-933A-286E463E72D8',
      }.merge(payload[:metadata] || {}),
    )
  rescue Stripe::StripeError => e
    status 402
    return log_info("Error creating PaymentIntent: #{e.message}")
  end

  log_info("PaymentIntent successfully created: #{payment_intent.id}")
  status 200
  return {
    :intent => payment_intent.id,
    :secret => payment_intent.client_secret,
    :status => payment_intent.status
  }.to_json
end

给出了这个后端代码，我试图通过编写这个方法来实现我的前端post，在这个方法中，我有一个参数，该参数是字符串形式的金额，例如“1099”，用于字符串，以便通过这个alamofire post请求将其发布到后端

func createPaymentIntent(sub: String? = nil, completion: @escaping STPJSONResponseCompletionBlock) {
            var url = URL(string: backendURL)!
            url.appendPathComponent("create_payment_intent")
            
            Alamofire.request(url, method: .post, parameters: ["sub": sub])
                .validate(statusCode: 200..<500)
                .responseJSON { (response) in
                    switch (response.result) {
                    case .failure(let error):
                        completion(nil, error)
                    case .success(let json):
                        completion(json as? [String : Any], nil)
                    }
            }
            
        }

每当我这样做的时候，我会得到一个错误

responseSerializationFailed(reason: Alamofire.AFError.ResponseSerializationFailureReason.jsonSerializationFailed(error: Error Domain=NSCocoaErrorDomain Code=3840 "Invalid value around character 0." UserInfo={NSDebugDescription=Invalid value around character 0.}))

我的Stripe Dashboard显示PaymentIntent从来不是由后端创建的，这意味着变量的发布一定不起作用

我该怎么做才能解决这个问题？如何将可变金额发布到后端进行处理

responseSerializationFailed(reason: Alamofire.AFError.ResponseSerializationFailureReason.jsonSerializationFailed(error: Error Domain=NSCocoaErrorDomain Code=3840 "Invalid value around character 0." UserInfo={NSDebugDescription=Invalid value around character 0.}))