问带有InAppPurchase &2目标的iOS应用程序

EN

func startBuyingProducts() {
    let purchaseRequest = SKProductsRequest(productIdentifiers: Set<String>(arrayLiteral:productID))
    purchaseRequest.delegate = self
    purchaseRequest.start()
}

// SKPridcutsRequestDelegate method
func productsRequest(_ request: SKProductsRequest, didReceive response: SKProductsResponse) {
    if let product = response.products.first {
        if SKPaymentQueue.canMakePayments() {
            let payment = SKPayment(product: product)
            SKPaymentQueue.default().add(self)
            SKPaymentQueue.default().add(payment)
        }
    }    


//implement method of SKPaymentTransactionObserver 
//trigger the unlock feature method when the purchase succeed and the receipt return is verified through apple
func paymentQueue(_ queue: SKPaymentQueue, updatedTransactions transactions: [SKPaymentTransaction]) {
    for transaction in transactions {
        switch transaction.transactionState {
            case .purchased:
                if let receiptURL = Bundle.main.appStoreReceiptURL {
                    let request = URLSession.shared.dataTask(with: receiptURL, completionHandler: { (data, response, error) in
                        let receiptJSON = data?.base64EncodedString(options: Data.Base64EncodingOptions.init(rawValue: 0))

                        //verify the receipt throught apple, or sending the verification throught your own server
                        var request = URLRequest(url: URL(string:"https://sandbox.itunes.apple.com/verifyReceipt")!)
                        request.setValue("application/json", forHTTPHeaderField: "Content-Type")
                        request.httpMethod = "POST"
                        request.httpBody = receiptJSON?.data(using: String.Encoding.utf8)
                        let task = URLSession.shared.dataTask(with: request, completionHandler: { (data, response, error) in
                            // unlock the feature here
                        })
                    })
                }
                SKPaymentQueue.default().finishTransaction(transaction)
                break
            case .failed:
                SKPaymentQueue.default().finishTransaction(transaction)
                break
            case .deferred:
                break
            case .purchasing:
                break
            case .restored: break
        }
    }
}