在 Swift 中使用 SKProduct() 的应用购买问题

Question

我正在尝试将应用内购买实现到我正在创建的应用中，但是当我尝试“获取”我拥有的产品时 var products = [SKProducts]() 但是这会返回一个空数组，导致应用程序崩溃。 我已经检查了所有税收协议等，当我在应用程序购买示例项目中的苹果中测试它时，IAP 就会出现。

出现问题的完整代码如下。

class Model {

        var products = [SKProduct]()

        func getProduct(containing keyword: String) -> SKProduct? {
            // print("The array of SKProducts in Model getProduct is \(products)")
            // let test = products.filter { $0.productIdentifier.contains(keyword) }.first
            print("The products are: \(products)")
            print(products.filter { $0.productIdentifier.contains(keyword) }.first)
            return products.filter { $0.productIdentifier.contains(keyword) }.first
        }
    }

打印语句返回： “产品是：[]”和 “无”

如果对整个项目有帮助，可以在 GitHub 上找到 here

Answer 1

getProduct 函数除了打印一个空数组 (products) 并过滤这个空数组并检索第一个元素（它不存在）之外什么都不做。
我建议使用这样的助手（我从某个地方复制的，不记得在哪里）：

import Foundation
import StoreKit

class IAPHelper: NSObject, SKProductsRequestDelegate, SKPaymentTransactionObserver {

  typealias RequestProductsCompletionHandler = (_ success:Bool, _ products:[SKProduct]?) -> ()
  var completionHandler: RequestProductsCompletionHandler?
  var productsRequest: SKProductsRequest?
  var productIdentifiers: Set<String>
  var purchasedProductIdentifiers: Set<String>?

  // MARK: - Init  

  init(identifiers: Set<String>) {

    // Store product identifiers
    productIdentifiers = identifiers;

    // Check for previously purchased products
    purchasedProductIdentifiers = Set()
    for productIdentifier in productIdentifiers {
      let productPurchased = UserDefaults.standard.bool(forKey: productIdentifier)
      if productPurchased {
        purchasedProductIdentifiers?.insert(productIdentifier)
                print("Previously purchased: \(productIdentifier)");
      } else {
                print("Not purchased: \(productIdentifier)");
      }
    }
    super.init() // must be called after subclass init, but before "self" is used
    SKPaymentQueue.default().add(self)
  } // init

  func requestProductsWithCompletionHandler(_ completionHandler: @escaping RequestProductsCompletionHandler) {
    self.completionHandler = completionHandler

    productsRequest = SKProductsRequest.init(productIdentifiers: productIdentifiers)
    productsRequest!.delegate = self
    productsRequest!.start()
  }

  // MARK: - Products request delegate

  func productsRequest(_ request: SKProductsRequest, didReceive response: SKProductsResponse) {
    productsRequest = nil

    let skProducts = response.products
        for skProduct in skProducts {
            print("Found product: \(skProduct.productIdentifier), \(skProduct.localizedTitle), \(skProduct.price.floatValue)");
    }

    completionHandler!(true, skProducts)
    completionHandler = nil
  }

  func request(_ request: SKRequest, didFailWithError error: Error) {
        // NOTE: If this happens on the simulator, close the simulator window and re-run the app. This helps normally !!!
        print("Failed to load list of products. Error: \(error)")
    productsRequest = nil

    completionHandler!(false, nil)
    completionHandler = nil
  }

  // MARK: - Purchase

  func productPurchchased(_ productIdentifier:String) -> Bool {
    return purchasedProductIdentifiers!.contains(productIdentifier)
  }

  func buyProduct(_ product:SKProduct) {
        print("Buying \(product.productIdentifier)");

    let payment = SKPayment(product: product)
    SKPaymentQueue.default().add(payment)
  }

  func paymentQueue(_ queue: SKPaymentQueue, updatedTransactions transactions: [SKPaymentTransaction]) {
    for transaction in transactions {
      switch transaction.transactionState {
      case SKPaymentTransactionState.purchased:
        self.completeTransaction(transaction)

      case SKPaymentTransactionState.failed:
        self.failedTransaction(transaction)

      case SKPaymentTransactionState.restored:
        self.restoreTransaction(transaction)

      default:
        print("Error: Unknown SKPaymentTransactionState")
      }
    }
  }

    func completeTransaction(_ transaction:SKPaymentTransaction) {
        print("completeTransaction...");

        self.provideContentForProductIdentifier(transaction.payment.productIdentifier)
        SKPaymentQueue.default().finishTransaction(transaction)
    }

    func restoreTransaction(_ transaction:SKPaymentTransaction) {
        print("restoreTransaction...");

        self.provideContentForProductIdentifier(transaction.original!.payment.productIdentifier)
        SKPaymentQueue.default().finishTransaction(transaction)
    }

    func failedTransaction(_ transaction:SKPaymentTransaction) {
        print("failedTransaction...");
        if let error = transaction.error as NSError?, error.code == SKError.paymentCancelled.rawValue {
                print("Transaction error:\(error.localizedDescription)");
        }

        SKPaymentQueue.default().finishTransaction(transaction)
    }

    func provideContentForProductIdentifier(_ productIdentifier:String) {

        purchasedProductIdentifiers?.insert(productIdentifier)
    UserDefaults.standard.set(true, forKey:productIdentifier)
    NotificationCenter.default.post(name: Notification.Name(rawValue: IAPHelperProductPurchasedNotification), object: productIdentifier, userInfo: nil)
  }

  func restoreCompletedTransactions() {
    SKPaymentQueue.default().restoreCompletedTransactions()
  }

}

Answer 2

要获得产品，您必须制作 SKProductsRequest 并在 SKProductsRequestDelegate 方法中等待答案。

创建并启动请求：

let request = SKProductsRequest(productIdentifiers: ids)
request.delegate = self // self is delegate of SKProductsRequestDelegate, see below
request.start()

ids 必须是 Set<String> 的产品标识符。

符合SKProductsRequestDelegate:

extension MyClass: SKProductsRequestDelegate {

    internal func productsRequest(_ request: SKProductsRequest, didReceive response: SKProductsResponse) {
        print(response.products) // here is your [SKProduct] array
        print(response.invalidProductIdentifiers) // if you put wrong ids they would be here
    } 

    internal func request(_ request: SKRequest, didFailWithError error: Error) {
        print(error) // something wrong
    }
}