如何检查iap交易是否完成？

Question

我正在使用https://pub.dev/packages/flutter_inapp_purchase 这个包进行应用内购买。我出售了积分，但用户可以获得比他们支付的更多的积分，如此视频所示：

https://youtu.be/Bo5MQdi5wGY

我该如何修复这个错误？请帮帮我。谢谢。

所有相关的代码行都在下面；

代码：

Future<void> initPlatformState() async {

await Purchases.setDebugLogsEnabled(true);
await Purchases.setup("RowkOdfhhydoMREZKRckltCNUNzJqgnj");
String platformVersion;
try {
  platformVersion = await FlutterInappPurchase.instance.platformVersion;
} on PlatformException {
  platformVersion = 'Failed to get platform version.';
}
var result = await FlutterInappPurchase.instance.initConnection;
print('result: $result');
if (!mounted) return;

setState(() {
  _platformVersion = platformVersion;
});

try {
  String msg = await FlutterInappPurchase.instance.consumeAllItems;
  print('consumeAllItems: $msg');

} catch (err) {
  print('consumeAllItems error: $err');
}
_conectionSubscription =
    FlutterInappPurchase.connectionUpdated.listen((connected) {
      print('connected: $connected');

    });




_purchaseUpdatedSubscription =
    FlutterInappPurchase.purchaseUpdated.listen((productItem) {
      // String deviceId = await PlatformDeviceId.getDeviceId;

      dispose();
      initPlatformState();

      //FlutterInappPurchase.instance.finishTransaction(productItem);



      if (productItem.productId == "oddinbetcredit10") {

        print("CREDİT 10 !!!");

        addCredit(deviceid, "10").then((value) => {

          tipController.updateCredit(),
        Fluttertoast.showToast(
        msg: "Successfully loaded 10 credit !...",
        toastLength: Toast.LENGTH_SHORT,
        gravity: ToastGravity.SNACKBAR,
        timeInSecForIosWeb: 1,
        backgroundColor: Colors.red,
        textColor: Colors.white,
        fontSize: 16.0
        )
        });

      } else if (productItem.productId == "oddinbetcredit20") {
        print("CREDİT 20 !!!");

        addCredit(deviceid, "20").then((value) => {



          tipController.updateCredit(),
        Fluttertoast.showToast(
        msg: "20 credits successfully loaded !...",
        toastLength: Toast.LENGTH_SHORT,
        gravity: ToastGravity.SNACKBAR,
        timeInSecForIosWeb: 1,
        backgroundColor: Colors.red,
        textColor: Colors.white,
        fontSize: 16.0
        )
        });


      } else if (productItem.productId == "oddinbetcredit50") {
        print("CREDİT 50 !!!");

        addCredit(deviceid, "50").then((value) => {

          tipController.updateCredit(),
        Fluttertoast.showToast(
        msg: "50 credits successfully loaded !...",
        toastLength: Toast.LENGTH_SHORT,
        gravity: ToastGravity.SNACKBAR,
        timeInSecForIosWeb: 1,
        backgroundColor: Colors.red,
        textColor: Colors.white,
        fontSize: 16.0
        )
        });


      } else if (productItem.productId == "oddinbetcredit100") {
        print("CREDİT 100 !!!");

        addCredit(deviceid, "100").then((value) => {

          tipController.updateCredit(),
        Fluttertoast.showToast(
        msg: "100 crdits successfully loaded!...",
        toastLength: Toast.LENGTH_SHORT,
        gravity: ToastGravity.SNACKBAR,
        timeInSecForIosWeb: 1,
        backgroundColor: Colors.red,
        textColor: Colors.white,
        fontSize: 16.0
        )

        });


      }  else if (productItem.productId == "oddinbetcreditvip"){


        isPremium = true;
        Fluttertoast.showToast(
            msg: "VIP successfully loaded!...",
            toastLength: Toast.LENGTH_SHORT,
            gravity: ToastGravity.SNACKBAR,
            timeInSecForIosWeb: 1,
            backgroundColor: Colors.red,
            textColor: Colors.white,
            fontSize: 16.0
        );


      }
    });

_purchaseErrorSubscription =
    FlutterInappPurchase.purchaseError.listen((purchaseError) {
      print('purchase-error: $purchaseError');
    });

}

Answer 1

其实这是这个插件的一个BUG，在Github上还是开放的

您获得更多积分的原因是因为 purchaseUpdated 侦听器在 iOS 上收到多个回调，因此您的 addCredit() 函数被多次调用。

作为一种解决方法，您可以使用 transactionId 作为标志，并避免多次调用 purchaseUpdated 侦听器内的代码。

添加支票

if(lastTransactionId!=productItem.transactionId)  

并在if语句体之外初始化lastTransactionId

 lastTransactionId = productItem.transactionId;

完整代码：

声明一个全局变量

String lastTransactionId;

然后用这个更新你的监听器代码

_purchaseUpdatedSubscription =
    FlutterInappPurchase.purchaseUpdated.listen((productItem) {
      // String deviceId = await PlatformDeviceId.getDeviceId;
      if(lastTransactionId!=productItem.transactionId){  //Added this to avoid multiple callbacks for the same transaction
        
      dispose();
      initPlatformState();

      //FlutterInappPurchase.instance.finishTransaction(productItem);



      if (productItem.productId == "oddinbetcredit10") {
        print("CREDİT 10 !!!");
        addCredit(deviceid, "10").then((value) => {
          tipController.updateCredit(),
        Fluttertoast.showToast(
        msg: "Successfully loaded 10 credit !...",
        toastLength: Toast.LENGTH_SHORT,
        gravity: ToastGravity.SNACKBAR,
        timeInSecForIosWeb: 1,
        backgroundColor: Colors.red,
        textColor: Colors.white,
        fontSize: 16.0
        )
        });

      } else if (productItem.productId == "oddinbetcredit20") {
        print("CREDİT 20 !!!");
        addCredit(deviceid, "20").then((value) => {
          tipController.updateCredit(),
        Fluttertoast.showToast(
        msg: "20 credits successfully loaded !...",
        toastLength: Toast.LENGTH_SHORT,
        gravity: ToastGravity.SNACKBAR,
        timeInSecForIosWeb: 1,
        backgroundColor: Colors.red,
        textColor: Colors.white,
        fontSize: 16.0
        )
        });
      } else if (productItem.productId == "oddinbetcredit50") {
        print("CREDİT 50 !!!");
        addCredit(deviceid, "50").then((value) => {
          tipController.updateCredit(),
        Fluttertoast.showToast(
        msg: "50 credits successfully loaded !...",
        toastLength: Toast.LENGTH_SHORT,
        gravity: ToastGravity.SNACKBAR,
        timeInSecForIosWeb: 1,
        backgroundColor: Colors.red,
        textColor: Colors.white,
        fontSize: 16.0
        )
        });

      } else if (productItem.productId == "oddinbetcredit100") {
        print("CREDİT 100 !!!");
        addCredit(deviceid, "100").then((value) => {
          tipController.updateCredit(),
        Fluttertoast.showToast(
        msg: "100 crdits successfully loaded!...",
        toastLength: Toast.LENGTH_SHORT,
        gravity: ToastGravity.SNACKBAR,
        timeInSecForIosWeb: 1,
        backgroundColor: Colors.red,
        textColor: Colors.white,
        fontSize: 16.0
        )
        });
      }  else if (productItem.productId == "oddinbetcreditvip"){
        isPremium = true;
        Fluttertoast.showToast(
            msg: "VIP successfully loaded!...",
            toastLength: Toast.LENGTH_SHORT,
            gravity: ToastGravity.SNACKBAR,
            timeInSecForIosWeb: 1,
            backgroundColor: Colors.red,
            textColor: Colors.white,
            fontSize: 16.0
        );
      }
      }
      lastTransactionId = productItem.transactionId; //finally initialize your lastTransactionId with productItem.transactionId, outside the if statement
    });

PS：你应该只调用一次await FlutterInappPurchase.instance.initConnection; 方法。

我希望这个答案有帮助！