我正在使用“ Omnipay與PayPal Express Checkout [symfony2.5]集成”，這是對課程的暗示命名空間Atcop \ BookBundle \ Libs;使用Omnipay \ Common \ GatewayFactory;貝寶類{protected $gateway = null;private static $CURRENCY = "USD";public function __construct() {    $this->gateway = GatewayFactory::create('PayPal_Express');    $this->gateway->setUsername('*********');    $this->gateway->setPassword('**********');    $this->gateway->setSignature('**************');    $this->gateway->setTestMode(true);}public function sendPurchase($parameters = []){    $payArray = [        'amount' => 58.00,        'description' => $parameters['description'],        'currency' => self::$CURRENCY,        'transactionId' => $parameters['transactionId'],        'returnUrl' => $parameters['returnUrl'],        'cancelUrl' => $parameters['cancelUrl']    ];    return $this->gateway->purchase($payArray)->send();}public function complete($reference, $payerId) {    $completePayData = [        'amount' => 58.00,        'description' => 'Buy the currencies book - step by step',        'transactionReference' => $reference,        'payerId' => $payerId,    ];    $response = $this->gateway->completePurchase($completePayData)->send();    if($response->isSuccessful()){        return $response->getData();    }    return false;}}完成后一切都很好，我在儀表板上看到該交易的通知和收據(jù)，但商人和買方的余額沒有變化。