Paypal自适应支付php

At some point in the process (Making test requests), I've tested it in a bash console, and my userid, password and signature worked. So I figure that the problem was in the code I was using.

代码如下:

<?php
class PaypalTest extends CComponent{

public $api_user = "**********************";
public $api_pass = "***********";
public $api_sig = "**************************";
public $app_id = "APP-80W284485P519543T";
public $apiUrl = 'https://svcs.sandbox.paypal.com/AdaptivePayments/';
public $paypalUrl="https://www.paypal.com/webscr?cmd=_ap-payment&paykey=";
public $headers;

public function __construct(){
    $this->headers = array(
        "X-PAYPAL-SECURITY-USERID: ".$this->api_user,
        "X-PAYPAL-SECURITY-PASSWORD: ".$this->api_pass,
        "X-PAYPAL-SECURITY-SIGNATURE: ".$this->api_sig,
        "X-PAYPAL-REQUEST-DATA-FORMAT: JSON",
        "X-PAYPAL-RESPONSE-DATA-FORMAT: JSON",
        "X-PAYPAL-APPLICATION-ID: ".$this->app_id,
    );
}

public function getPaymentOptions($paykey){

}
public function setPaymentOptions(){

}
public function _paypalSend($data,$call){
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $this->apiUrl.$call);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
    curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);
    curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($data));
    curl_setopt($ch, CURLOPT_HEADER, $this->headers);
    $response = json_decode(curl_exec($ch),true);
    return $response;

}
public function splitPay(){

    // create the pay request
    $createPacket = array(
        "actionType" =>"PAY",
        "currencyCode" => "USD",
        "receiverList" => array(
            "receiver" => array(
                array(
                    "amount"=> "1.00",
                    "email"=>"********@hotmail.com"
                ),
                array(
                    "amount"=> "2.00",
                    "email"=>"********@gmail.ca"
                ),
            ),
        ),
        "returnUrl" => "http://test.local/payments/confirm",
        "cancelUrl" => "http://test.local/payments/cancel",
        "requestEnvelope" => array(
            "errorLanguage" => "en_US",
            "detailLevel" => "ReturnAll",
        ),
    );

    $response = $this->_paypalSend($createPacket,"Pay");
}
}

这是电话:

$payment = new PaypalTest();
$payment->splitPay();

很简单，但有些东西不起作用.而且我对 Curl 不是很熟悉，所以我想你们可以帮助我