Paypal 自适应付款返回网址调用两次

我已经实现了贝宝自适应支付方法并使用网络流程。 付款后，当我明确单击返回按钮时，返回网址会调用两次，但如果我等待自动重定向，则它只会调用一次。

我无法理解为什么 return url 调用了两次。

请指教。

我正在使用下面的代码。

public static ActionOutput MakeTransactionUsingPaypal(PaymentDetails payment, ShopCart shop_cart)
{
    ReceiverList receiverList = new ReceiverList();
    receiverList.receiver = new List<Receiver>();
    string action_type = "PAY_PRIMARY";
    decimal amnt_to_admin = ((shop_cart.TotalAmountToBePaid * 10) / 100);

    /*Total Amount to Admin Account */
    Receiver rec1 = new Receiver(shop_cart.TotalAmountToBePaid);
    rec1.email = Config.AdminPaypalBusinessAccount;
    rec1.primary = true;

    /*Amount after deducting to Admin Commision to Seller */
    Receiver rec2 = new Receiver(Math.Round((shop_cart.TotalAmountToBePaid - amnt_to_admin), 2, MidpointRounding.ToEven));
    rec2.email = payment.PaypalEmail; // "[email protected]";

    receiverList.receiver.Add(rec1);
    receiverList.receiver.Add(rec2);
    PayRequest req = new PayRequest(new RequestEnvelope("en_US"), action_type, Config.PaypalCancelURL, "USD", receiverList, Config.PaypalReturnURL);

    // All set. Fire the request            
    AdaptivePaymentsService service = new AdaptivePaymentsService();

    PayResponse resp = null;
    //TransactionDetail details = new TransactionDetail();

    resp = service.Pay(req);
    String PayKey = resp.payKey;
    String PaymentStatus = resp.paymentExecStatus;
    ResponseEnvelope ResponseEnvelope = resp.responseEnvelope;
    PayErrorList errorList = resp.payErrorList;
    List<ErrorData> errorData = resp.error;
    if (errorData.Count > 0)
    {
        return new ActionOutput
        {
            Status = ActionStatus.Error,
            Message = errorData[0].message
        };
    }
    FundingPlan defaultFundingPlan = resp.defaultFundingPlan;
    WarningDataList warningDataList = resp.warningDataList;
    string redirectUrl = null;
    if (!(resp.responseEnvelope.ack == AckCode.FAILURE) &&
        !(resp.responseEnvelope.ack == AckCode.FAILUREWITHWARNING))
    {
        redirectUrl = ConfigurationManager.AppSettings["PAYPAL_REDIRECT_URL"] + "_ap-payment&paykey=" + resp.payKey;

    }
    return new ActionOutput
    {
        Status = ActionStatus.Successfull,
        Message = "Redirecting to paypal...",
        Results = new List<string> { redirectUrl, resp.payKey }
    };
}

@jitendra，我遇到了同样的问题，发现贝宝使用服务器端脚本，该脚本在一段时间后将用户重定向到返回网址，当我们明确单击返回按钮时，贝宝服务器脚本再次点击返回网址它自己的，因此我们在返回网址上得到了两次响应/点击。

我们可以通过检查/维护在贝宝上付款后收到的回复数来解决这个问题。

我们可以使用客户端上的 cookie 或使用会话或其他类似的东西在服务器上维护它。

希望这有帮助。