您可以在将参数发布到贝宝后查看交易状态，并返回响应错误或成功消息。下面是一个完整的支付流程示例，包括定期支付和普通支付之后：
// SetExpressCheckout 的参数，将发送到 PayPal
$pada['L_BILLINGAGREEMENTDESCRIPTION0'] = '产品描述';
$pada['L_BILLINGAGREEMENTDESCRIPTION0'] = $pada['L_BILLINGAGREEMENTDESCRIPTION0'] 。
'$'.$product->price.'/month';
$padata['L_PAYMENTREQUEST_0_DESC0'] = $padata['L_BILLINGAGREEMENTDESCRIPTION0'] 。
'$'.$product->price.'/month';
$padata['PAYMENTREQUEST_0_NOTIFYURL'] = 'http://site_url/paypal/ipn';
$padata['PAYMENTREQUEST_0_DESC'] = $product->name;
$padata['RETURNURL'] = 'http://site_url/paypal/returnurl';
$padata['CANCELURL'] = 'http://site_url/paypal/cancelurl';
$pada['PAYMENTREQUEST_0_CURRENCYCODE'] = 'USD';
$pada['PAYMENTREQUEST_0_PAYMENTACTION'] = '销售';
$padata['PAYMENTREQUEST_0_ITEMAMT'] = $product->price;
$padata['PAYMENTREQUEST_0_AMT'] = $product->price;
$padata['L_BILLINGTYPE0'] = 'RecurringPayments';
$ padata['L_PAYMENTREQUEST_0_NAME0'] = $product->name;
$padata['L_PAYMENTREQUEST_0_NUMBER0']= '322';
$padata['L_PAYMENTREQUEST_0_QTY0'] = '1';
$padata[' L_PAYMENTREQUEST_0_AMT0'] = $产品->价格；
$paypal_data = http_build_query($pada);
$httpParsedResponseAr = $this->PPHttpPost('SetExpressCheckout', $paypal_data);
//根据我们从 Paypal 收到的消息进行响应
if("SUCCESS" == strtoupper($httpParsedResponseAr["ACK"]) || "SUCCESSWITHWARNING" == strtoupper($httpParsedResponseAr["ACK"])){
//使用收到的令牌将用户重定向到 PayPal 商店。
$paypalurl ='https://www.paypal.com/cgi-bin/webscr?cmd=_express-checkout&token='.$httpParsedResponseAr["TOKEN"].'';
header('位置：'.$paypalurl);
}别的{
echo '
错误：'.urldecode($httpParsedResponseAr["L_LONGMESSAGE0"]).'';
}
页面返回网址：
$hosteddata['L_BILLINGAGREEMENTDESCRIPTION0'] = '重复描述';
$hosteddata['L_BILLINGAGREEMENTDESCRIPTION0'] = $hosteddata['L_BILLINGAGREEMENTDESCRIPTION0'] 。 '$'.$pr->price.'/month';
$hosteddata['L_PAYMENTREQUEST_0_NAME0'] = $pr->name;
$hosteddata['PROFILEREFERENCE'] = $GetExpressCheckoutDetails['L_PAYMENTREQUEST_0_NUMBER0'] ;
$hosteddata['PROFILESTARTDATE'] = date('Ym-d') 。 'T'。 date('H:i:s').'Z';
$hosteddata['SUBSCRIBERNAME'] = $GetExpressCheckoutDetails['FIRSTNAME'] 。 ' ' 。 $GetExpressCheckoutDetails['LASTNAME'];
$hosteddata['TOKEN'] = urlencode($_POST['token']);
$hosteddata['DESC'] = $hosteddata['L_BILLINGAGREEMENTDESCRIPTION0'];$hosteddata['AMT'] = $pr->price;
$hosteddata['BILLINGPERIOD'] = '月';
$hosteddata['BILLINGFREQUENCY'] = '1';
$ hostsdata['TOTALBILLINGCYCLES'] = '12';
$hosteddata['REGULARTOTALBILLINGCYCLES'] = '1';
$hosteddata['VERSION'] = '74.0';
$hosteddata['MAXFAILEDPAYMENTS' ] = '1';
$hosteddata['L_PAYMENTREQUEST_0_QTY0'] = '1';
$hosteddata['L_BILLINGTYPE0'] = 'RecurringPayments';
$hosteddata['L_PAYMENTREQUEST_0_ITEMCATEGORY0'] = '数字' ;
$hosteddata['L_PAYMENTREQUEST_0_AMT0'] = $pr->price;
$hosteddata['INITAMT'] = $pr->price;
$hosteddata['L_PAYMENTREQUE ST_0_NUMBER0'] = $pr->id;
$hosteddata['PAYMENTREQUEST_0_NOTIFYURL'] = 'http://site_url/paypal/ipn';
$paypal_data = http_build_query($hosteddata);
$hosted_saas_response = $this->PPHttpPost('CreateRecurringPaymentsProfile', $paypal_data);
我使用单独的方法将参数发布到贝宝
私有函数 PPHttpPost( $methodName_, $nvpStr_ ) {
$api_username = 'yourpaypal@email.com';
$api_password = 'QWEQWEWQEQWEQEQWE';
$api_signature = 'WQEQWEQWEQWEWQEQWEQWEQWEQWEQWE.cT';
$api_endpoint = "https://api-3t.paypal.com/nvp";
$version = '124.0' ;
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $api_endpoint);
curl_setopt($ch, CURLOPT_VERBOSE, 1);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, FALSE);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_POST, 1);
$nvpreq = "METHOD=$methodName_&VERSION=$version&PWD=$api_password&USER=$api_username&SIGNATURE=$api_signature&$nvpStr_";
curl_setopt($ch, CURLOPT_POSTFIELDS, $nvpreq);
$httpResponse = curl_exec($ch);
如果（！$http响应）{
exit("$methodName_ failed: ".curl_error($ch).'('.curl_errno($ch).')');
}
// 提取响应详细信息。
$httpResponseAr = explode("&", $httpResponse);
$httpParsedResponseAr = 数组（）；
foreach ($httpResponseAr as $i => $value) {
$tmpAr = explode("=", $value);
如果（大小（$tmpAr）> 1）{
$httpParsedResponseAr[$tmpAr[0]] = $tmpAr[1];
}
}
if((0 == sizeof($httpParsedResponseAr)) || !array_key_exists('ACK', $httpParsedResponseAr)) {
exit("对 $api_endpoint 的 POST 请求 ($nvpreq) 的 HTTP 响应无效。");
}
返回 $httpParsedResponseAr;
}
一次性普通支付SetExpressCheckout参数：
// 一次性普通支付SetExpressCheckout参数
$padata['L_BILLINGAGREEMENTDESCRIPTION0'] = '产品描述;
$padata['L_PAYMENTREQUEST_0_DESC0'] = $padata['L_BILLINGAGREEMENTDESCRIPTION0'];
$padata[ 'PAYMENTREQUEST_0_NOTIFYURL'] = 'http://siteurl.com/paypal/ipn';
$padata['PAYMENTREQUEST_0_DESC'] = $padata['L_BILLINGAGREEMENTDESCRIPTION0'];
$padata['RETURNURL'] = ' http://siteurl.com/paypal/returnToDownload';
$padata['CANCELURL'] = 'http://siteurl.com/paypal/cancelurl';
$padata['PAYMENTREQUEST_0_CURRENCYCODE'] = 'USD';
$padata['PAYMENTREQUEST_0_PAYMENTACTION'] = 'SALE';
$padata['PAYMENTREQUEST_0_ITEMAMT'] = $product->price;
$padata[ 'PAYMENTREQUEST_0_AMT'] = $product->price;
$padata['L_PAYMENTREQUEST_0_NAME0'] = $product->price;
$padata['L_PAYMENTREQUEST_0_NUMBER0'] = 'verification_id#@@#!@#!@#@!!@#ASDASD';
$padata['L_PAYMENTREQUEST_0_QTY0'] = '1';
$padata[' L_PAYMENTREQUEST_0_AMT0'] = $product->价格；