我读过关于同一主题的其他帖子，但我很确定我没有遇到这些帖子的问题。这真的让我很沮丧，所以任何帮助或建议都将不胜感激。
我正在构建下面的数组，以便在SetExpressCheckout调用中发送，但每次提交时，我都会得到"购物车项目金额的总和与订单金额不匹配"，但我不明白怎么回事！！
[METHOD] => SetExpressCheckout
[USER] => myusername
[PWD] => 1398341028
[SIGNATURE] => xxxsignaturexxx
[VERSION] => 85.0
[RETURNURL] => http://www.mysite.dev/payment/process
[CANCELURL] => http://www.mysite.dev/payment/cancelled
[PAYMENTREQUEST_0_PAYMENTACTION] => SALE
[NOSHIPPING] => 0
[PAYMENTREQUEST_0_AMT] => 189.00
[PAYMENTREQUEST_0_ITEMAMT] => 189.00
[PAYMENTREQUEST_0_TAXAMT] => 0
[PAYMENTREQUEST_0_SHIPPINGAMT] => 0
[PAYMENTREQUEST_0_HANDLINGAMT] => 0
[PAYMENTREQUEST_0_SHIPDISCAMT] => 0
[PAYMENTREQUEST_0_INSURANCEAMT] => 0
[PAYMENTREQUEST_0_CURRENCYCODE] => GBP
[LOCALECODE] => GB
[ALLOWNOTE] => 1
[L_PAYMENTREQUEST_0_NAME0] => Website Order
[L_PAYMENTREQUEST_0_NUMBER0] => 28424747
[L_PAYMENTREQUEST_0_AMT0] => 189.00
[L_PAYMENTREQUEST_0_QTY0] => 1
非常感谢您的阅读。Kris
我继续使用测试帐户测试您的调用，最初它给出了与您描述的类似的错误。我确实让它工作了，我所做的唯一修改是调用的格式和间隔。
这是我提交并得到成功响应的调用，请注意，我必须更改用户、密码、签名、版本、returnrul和cancelurl才能进行测试：
USER=chad_1311276857_biz_api1.x.com
PWD=NGAEWP367NNSDXP2
SIGNATURE=Aef0iZ4csmtdchFhBLFKNKS88OSVA0f08rNWMEUk1J-tsdbDOFq0JpNi
METHOD=SetExpressCheckout
VERSION=113.0
RETURNURL=http://ccaples.com/index.php/api-s/paypal-nvp/nvp-quick-test
CANCELURL=http://ccaples.com/index.php/api-s/paypal-nvp/nvp-quick-test
PAYMENTREQUEST_0_PAYMENTACTION=SALE
NOSHIPPING=0
PAYMENTREQUEST_0_AMT=189.00
PAYMENTREQUEST_0_ITEMAMT=189.00
PAYMENTREQUEST_0_TAXAMT=0
PAYMENTREQUEST_0_SHIPPINGAMT=0
PAYMENTREQUEST_0_HANDLINGAMT=0
PAYMENTREQUEST_0_SHIPDISCAMT=0
PAYMENTREQUEST_0_INSURANCEAMT=0
PAYMENTREQUEST_0_CURRENCYCODE=GBP
LOCALECODE=GB
ALLOWNOTE=1
L_PAYMENTREQUEST_0_NAME0=Website Order
L_PAYMENTREQUEST_0_NUMBER0=28424747
L_PAYMENTREQUEST_0_AMT0=189.00
L_PAYMENTREQUEST_0_QTY0=1