Php Handlng贝宝支付API响应

我希望这是提出这个问题的正确地点，但我似乎无法在文档中找到答案

我正在用PHP和Paypal实现一个支付解决方案

在处理PAYPAL帐户付款时，我按照此处所述的步骤进行操作：

完成这些步骤不是问题。我从成功的交易中获得了预期的结果

我的问题是在处理错误/付款失败时

根据文档，销售状态可以是：

Possible values: completed, partially_refunded, pending, refunded, denied.

什么会导致它被搁置？此外，挂起的销售状态是否会导致付款状态失败

我试图理解这两种状态是如何结合在一起并相互影响的。目的是妥善处理付款。知道何时批准/拒绝，以便我可以相应地处理

现在，我的测试代码如下：

$response = executePaypalPayment($token, $payer_id, $payment_id);

    //Get the state of the payment
    $payment_state = $response->state;

    //Get the state of the sale
    $sale_state = $response->transactions[0]->related_resources[0]->sale->state;

    if($payment_state == "approved" && $sale_state == "completed"){
        //Everything was successful
        $message = 'Your order was placed successfully! A confirmation email has been sent to the email address provided.';
        displayOrderScreenMessage($message);

    } else {
        //Something went wrong
        if($payment_state !== "approved"){
            //payment failed
            $message = "Unable to process payment. Please try again.";
            displayOrderScreenMessage($message, true, true);
        }

    }

问题是，我不知道如何确定付款的状态。感谢您的帮助。谢谢