swift - 我的恢复购买代码是否正确？如果正确，我应该在哪里执行更改用户默认值的操作？

Question

我正在用 Swift 编写我的第一个 iOS 应用程序，但应用程序内购买功能遇到了一些问题。我认为我已经可以使用实际的购买功能，但我不确定恢复功能。我只是提供一种产品，它是应用程序的“专业”版本。它存储在“用户默认值”位置，并通过它解锁额外的功能。我的恢复功能让我感到困惑，有人可以看一下它并告诉我应该在哪里设置用户默认值吗？它应该在 paymentQueueRestoreCompletedTransactionsFinished 函数内还是 paymentQueue 函数内？

import UIKit
import StoreKit

class StoreController: UIViewController, SKProductsRequestDelegate, 
SKPaymentTransactionObserver   {

// Properties
var defaults = UserDefaults.standard
var list = [SKProduct]()
var p = SKProduct()

// Methods
override func viewDidLoad() {
    super.viewDidLoad()
    // Get list of products for the store
    localTitle.isEnabled = false
    localDescription.isEnabled = false
    price.isEnabled = false
    buy.isEnabled = false
    restore.isEnabled = false
    getProducts()
}

// Outlets
@IBOutlet weak var localTitle: UILabel!
@IBOutlet weak var localDescription: UILabel!
@IBOutlet weak var price: UILabel!
@IBOutlet weak var buy: UIButton!
@IBOutlet weak var restore: UIButton!

// Actions
@IBAction func buy(_ sender: UIButton) {
    print("buy pressed")
    for product in list {
        let prodID = product.productIdentifier
        if(prodID == "com.squidgylabs.pro") {
            p = product
            buyProduct()
        }
    }
}

@IBAction func restore(_ sender: UIButton) {
    print("restore pressed")
    SKPaymentQueue.default().add(self)
    SKPaymentQueue.default().restoreCompletedTransactions()
}

// Methods
func getProducts() {
    print("starting  getproducts function")
    if(SKPaymentQueue.canMakePayments()) {
        print("IAP is enabled, loading")
        let productID: NSSet = NSSet(objects: "com.squidgylabs.pro")
        let request: SKProductsRequest = SKProductsRequest(productIdentifiers: productID as! Set<String>)
        request.delegate = self
        request.start()
    } else {
        print("please enable IAPS")
    }
}


func productsRequest(_ request: SKProductsRequest, didReceive response: SKProductsResponse) {
    print("starting productsrequest")
    let myProduct = response.products
    for product in myProduct {
        print("product added")
        list.append(product)
    }
    localTitle.isEnabled = true
    localDescription.isEnabled = true
    restore.isEnabled = true
    buy.isEnabled = true
    price.isEnabled = true

    // Update labels
    localTitle.text = list[0].localizedTitle
    localDescription.text = list[0].localizedDescription
    // Format the price and display
    let formatter = NumberFormatter()
    formatter.locale = Locale.current
    formatter.numberStyle = .currency
    if let formattedPrice = formatter.string(from: list[0].price){
        price.text = formattedPrice
    }
}


func paymentQueueRestoreCompletedTransactionsFinished(_ queue: SKPaymentQueue) {
    print("starting paymentQueueResoreCompletedTransactionsFnished")
    for transaction in queue.transactions {
        let t: SKPaymentTransaction = transaction
        let prodID = t.payment.productIdentifier as String

        switch prodID {
        case "com.squidgylabs.pro":
            print("case is correct product ID in payment...finished")

        default:
            print("IAP not found")
        }
    }
}

func buyProduct() {
    print("buy " + p.productIdentifier)
    let pay = SKPayment(product: p)
    SKPaymentQueue.default().add(self)
    SKPaymentQueue.default().add(pay as SKPayment)
}

func paymentQueue(_ queue: SKPaymentQueue, updatedTransactions transactions: [SKPaymentTransaction]) {
    print("entering func paymentQueue")

    for transaction: AnyObject in transactions {
        let trans = transaction as! SKPaymentTransaction

        switch trans.transactionState {
        case .purchased:
            print("buy ok, unlock IAP HERE")

            print(p.productIdentifier)
            let prodID = p.productIdentifier
            switch prodID {
            case "com.squidgylabs.pro":
                print("setting pro in defaults...")
                defaults.set(true, forKey: "pro")
            default:
                print("IAP not found")
            }
            queue.finishTransaction(trans)
            break
        case .failed:
            print("buy error")
            queue.finishTransaction(trans)
            break
        case .restored:
            print("case .restored in paymentQ")
            SKPaymentQueue.default().finishTransaction(transaction as! SKPaymentTransaction)
            queue.finishTransaction(trans)
            break
        default:
            print("Default")
            break
        }
    }
}
}

Answer 1

可以这样完成。

public func paymentQueue(_ queue: SKPaymentQueue, updatedTransactions transactions: [SKPaymentTransaction]) {
    for transaction in transactions {
        switch transaction.transactionState {
        case .purchased:
            completePurchaseForTransaction(transaction)
        case .restored:
            completePurchaseForTransaction(transaction)
        default:
            break
    }
}

private func completePurchaseForTransaction(_ transaction: SKPaymentTransaction) {
    let productIdentifier = transaction.payment.productIdentifier
    // Update UserDefaults here
    SKPaymentQueue.default().finishTransaction(transaction)
}

您可能会考虑使用其他类来访问 StoreKit，而不是 UIViewController。因为

Your application should always expect to be notified of completed transactions.

https://developer.apple.com/documentation/storekit/skpaymentqueue/1506042-add

View Controller 来来去去。如果您不删除作为观察者添加到 SKPaymentQueue 的对象，它甚至可能会使应用程序崩溃。

我在 GitHub 上有一个简单且文档齐全的 StoreKit 库，您可以查看它来了解想法 -- https://github.com/suvov/VSStoreKit