问题
We use PDT's cmd=_notify-synch API to validate transactions when the customer is redirect back to our website after a payment.
We pass a "custom" value in our Paypal buttons with a customer id, and we expect to get this value back. This worked fine for the past 5 years.
Starting on or around 2018/10/19, the PDT API stopped returning the "custom" value that was passed in. This broke our payment flow.
Not sure if anybody else ran into this issue, and/or if there's a workaround or a configuration to change.
回答1:
That button URL is for a hosted button, which means all of the parameters are set within PayPal when you create the button. You cannot pass a return value directly to a hosted button. You would need to adjust that in the hosted button itself within the PayPal account.
The only way to set it there would be with the Advanced Variables section, but of course you won't be able to make that dynamic. If this is a problem you're going to need to switch to using a non-hosted button so that you can then pass parameters directly the way you are trying to do.
Beyond that you could switch to using the Express Checkout API, and then you have more freedom and flexibility to do whatever you need during checkout.
来源：https://stackoverflow.com/questions/53013945/paypal-pdt-doesnt-return-custom-value-anymore-regression