问题
I need to include a custom field when PayPal notifies me of a payment. I'm trying to use the advanced variables, but I don't see a way that I can make them dynamic.
Pretend I have a field "xyzzy" with a value of "plugh". I would like PayPal to include form.xyzzy=plugh with all the other fields that it sends to my notify_url.
Of course, the value of xyzzy might be "foo", depending upon what they user wants.
回答1:
There's only "custom": input type="hidden" name="custom" value="plugh"
This is returned in the IPN message as well.
来源：https://stackoverflow.com/questions/6833192/custom-paypal-field-on-button