如何使用 in_app_purchase 包在 Flutter 中升级/降级订阅

Question

对于购买，我使用的是 inapppurchase 包。该软件包提供了升级和降级软件包的功能。但我无法升级或降级该软件包。我正在分享在他们的包裹页面上找到的详细信息。

*
目前，我一直在获取PurchaseDetails 对象(oldPurchaseDetails)。有人用过 in_app_purchase 包的这个功能吗？

我查看了该包代码并遵循了他们的共享代码。但我没有找到获取旧购买详细信息的方法。

Answer 1

要获取旧购买，您需要发送以前购买的计划 ID，然后您才能获取旧购买详细信息，这里的代码可能对您有帮助

 GooglePlayPurchaseDetails? _getOldSubscription(
      ProductDetails productDetails, Map<String, PurchaseDetails> purchases) {
    // This is just to demonstrate a subscription upgrade or downgrade.
    // Please remember to replace the logic of finding the old subscription Id as per your app.
    // The old subscription is only required on Android since Apple handles this internally
    // by using the subscription group feature in iTunesConnect.

     var _kSubscriptionId =
        "<Product ID which you want to purchase>";

    var _kPastSubscriptionId = "<Old Product ID which you already purchased>";

    GooglePlayPurchaseDetails? oldSubscription;
    if (productDetails.id == _kSubscriptionId &&
        purchases[_kPastSubscriptionId] != null) {
      oldSubscription =
          purchases[_kPastSubscriptionId]! as GooglePlayPurchaseDetails;
    }
    return oldSubscription;
  }

这将返回旧的计划详细信息。

Answer 2

如果您不使用最新的东西对其进行测试，则该示例将无法工作。如果您将交易令牌存储在服务器上，请执行以下操作：

import 'package:in_app_purchase_android/in_app_purchase_android.dart';
import 'package:in_app_purchase_android/billing_client_wrappers.dart';



final verificationData = PurchaseVerificationData(localVerificationData: token!, serverVerificationData: token!, source: token!);

// the only thing here that matters for this object is token!
final wrapper = PurchaseWrapper.fromJson({
    "orderId": "",
    "packageName": "",
    "purchaseTime": 0,
    "purchaseToken": token!,
    "signature": "",
    "products": [],
    "isAutoRenewing": false,
    "originalJson": "",
    "isAcknowledged": false,
    "purchaseState": 0
  });

final oldPurchaseDetails = GooglePlayPurchaseDetails(
  productID: currentPlan!, <-- plan id for the old one
  verificationData: verificationData,
  transactionDate: DateTime.now().millisecondsSinceEpoch.toString(),
  billingClientPurchase: wrapper,
  status: PurchaseStatus.purchased,
);

不得不去了解源代码，但这里是这样你可以看看它是否会在未来发生变化或发生什么变化。希望这有帮助！

https://github.com/flutter/plugins/blob/557d3284ac9dda32a1106bb75be8a23bdccd2f96/packages/in_app_purchase/in_app_purchase_android/lib/src/in_app_purchase_android_platform.dart#L134