NSObject, SKProductsRequestDelegate { // Define the product identifier for the app let productId = "YOUR_PRODUCT_IDENTIFIER" override init() { super.init() // Set up the product request let request = SKProductsRequest(productIdentifiers: Set([productId])) request.delegate = self request.start() } func productsRequest(_ request: SKProductsRequest, didReceive response: SKProductsResponse) { // Check if the product is 影音ailable if let product = response.products.first { print("Found product: \(product.productIdentifier)") // Initiate the purchase let payment = SKPayment(product: product) SKPaymentQueue.default().add(payment) } else { print("Product not found") } } func request(_ request: SKRequest, didFailWithError error: Error) { print("Error retrieving product: \(error)") } } ``` Android ```kotlin import com.android.billingclient.api. class AppDownloadManager(val context: Context) : PurchasesUpdatedListener { // Define the product identifier for the app val productId = "YOUR_PRODUCT_IDENTIFIER" // Create the BillingClient private val billingClient = BillingClient.newBuilder(context).setListener(this).build() init { // Connect to the Play Store billingClient.startConnection(object : BillingClientStateListener { override fun onBillingSetupFinished(billingResult: BillingResult) { if (billingResult.responseCode == BillingClient.BillingResponseCode.OK) { // The billing client is ready to use querySkuDetails() } } override fun onBillingServiceDisconnected() { // The billing service was disconnected } }) } private fun querySkuDetails() { val skuDetailsParams = SkuDetailsParams.newBuilder() .setSkusList(listOf(productId)) .setType(BillingClient.SkuType.INAPP) .build() billingClient.querySkuDetailsAsync(skuDetailsParams) { billingResult, skuDetailsList -> if (billingResult.responseCode == BillingClient.BillingResponseCode.OK) { // The SKU details are 影音ailable val skuDetails = skuDetailsList?.first { it.sku == productId } if (skuDetails != null) { purchase(skuDetails) } } } } private fun purchase(skuDetails: SkuDetails) { val purchaseParams = BillingFlowParams.newBuilder() .setSkuDetails(skuDetails) .build() billingClient.launchBillingFlow(context, purchaseParams) } override fun onPurchasesUpdated(billingResult: BillingResult, purchases: List?) { // Handle the purchase results } } ```