android - 使用 Google Play Billing，是否可以等到确认购买后再授予应用内购买的权利？

Question

Google Play Billing library关于 acknowledging purchases 的文档指出:

you must acknowledge all purchases that have a SUCCESS state received through the Google Play Billing Library as soon as possible after granting entitlement to the user.

因此，您的应用应首先向用户提供他购买的商品，然后确认购买。这也是他们的示例代码所暗示的:

fun handlePurchase() {
    if (purchase.purchaseState === PurchaseState.PURCHASED) {
        // Grant entitlement to the user.
        ...
        // Acknowledge the purchase if it hasn't already been acknowledged.
        if (!purchase.isAcknowledged) {
            val acknowledgePurchaseParams = AcknowledgePurchaseParams.newBuilder()
                    .setPurchaseToken(purchase.purchaseToken)
                    .build()
            client.acknowledgePurchase(acknowledgePurchaseParams, acknowledgePurchaseResponseListener)
        }
    }
}

我目前正在开发一个 Android 应用程序，我允许用户访问他们购买的内容之后以 OK 状态返回的确认(反之亦然):

private fun acknowledgePurchase(purchase: Purchase) {
    val params = AcknowledgePurchaseParams.newBuilder()
        .setPurchaseToken(purchase.purchaseToken)
        .build()

    billingClient.acknowledgePurchase(params) { billingResult ->
        when (billingResult.responseCode) {
            BillingResponseCode.OK -> loadPurchase(purchase.sku)
            else -> { ... }
        }
    }
}

因为文档指出:

... you must acknowledge all purchases within three days. Failure to properly acknowledge purchases results in those purchases being refunded.

如果发生这种情况，并且用户获得退款，则用户对该产品的权利也应该被撤销。但就我而言，进行购买意味着加载数据、将内容存储在数据库中等等，而我没有，也不希望有适当的代码来恢复它。因此，我只在成功确认之后才向用户提供产品。

因此我的问题是:是否可以等到确认购买后再授予应用内购买的权利？还是我在这里遗漏了一些问题？我假设文档指定此顺序是有原因的，但他们没有详细说明。

Answer 1

经过更多研究后，我注意到 Trivial Drive sample app采用与我完全相同的方法。以下是 their code 的 fragment :

private fun acknowledgeNonConsumablePurchasesAsync(nonConsumables: List<Purchase>) {
    nonConsumables.forEach { purchase ->
        val params = AcknowledgePurchaseParams.newBuilder().setPurchaseToken(purchase
                .purchaseToken).build()
        playStoreBillingClient.acknowledgePurchase(params) { billingResult ->
            when (billingResult.responseCode) {
                BillingClient.BillingResponseCode.OK -> {
                    disburseNonConsumableEntitlement(purchase)
                }
                else -> Log.d(LOG_TAG, "acknowledgeNonConsumablePurchasesAsync response is ${billingResult.debugMessage}")
            }
        }

    }
}

如果响应正常，则表明在确认回调函数中授予了权利。与我问题中的代码完全相同。

所以我想问题的答案是:是的，确认成功后授予权利是可以的。