注意: 本文，只寫大體重要幾個步驟，不是很詳細。
仔細研究建議觀看:
In-App Purchase for Developer、
巧哥的(iOS應用內付費(IAP)開發(fā)步驟列表 、
Yi'mouleng、
如何正確使用IAP
等等......

創(chuàng)建你的 SkpayManager

導入 StoreKit庫

簽訂<SKPaymentTransactionObserver, SKProductsRequestDelegate>協(xié)議

SkpayManager:

1. 程序啟動添加SKPay觀察者，同時像后端請求產品列表信息

- (void)launch {
    [[SKPaymentQueue defaultQueue] addTransactionObserver:self];
    [self requestProductList];
}

2. 程序結束后，移除SKpay觀察者

- (void)terminate {
    [[SKPaymentQueue defaultQueue] removeTransactionObserver:self];
}

3. 這時候已請求拿到我們服務端給的產品信息,購買頁面可進行UI布局展示

UI展示

4. 進入購買頁面，通過用戶選擇的產品ID,以及quantity進行購買

- (void)buyProductsWithId:(NSString *)productsId andQuantity:(NSInteger)quantity {

    self.productsId = productsId;
    self.quantity = quantity;
    if ([SKPaymentQueue canMakePayments]) {
        //允許程序內付費購買
        [self RequestProductData:@[self.productsId]];
    } else {
        [[ZToastManager ShardInstance] showtoast:@"您的手機沒有打開程序內付費購買"];
    }
}

5. 然后通過用戶選中的產品ID數(shù)組，SKProductsRequest 開始請求購買

- (void)RequestProductData:(NSArray *)productsIdArr {
    //請求對應的產品信息
    NSSet *nsset = [NSSet setWithArray:productsIdArr];
    SKProductsRequest *request = [[SKProductsRequest alloc] initWithProductIdentifiers:nsset];
    request.delegate = self;
    [request start];
}

6. SKProductsRequestDelegate 會接收到請求響應，在此回調中，發(fā)送購買請求

//收到的產品信息
- (void)productsRequest:(SKProductsRequest *)request didReceiveResponse:(SKProductsResponse *)response {
    //收到產品反饋信息
    NSArray *myProduct = response.products;
//    NSLog(@"產品Product ID:%@", response.invalidProductIdentifiers);
//    NSLog(@"產品付費數(shù)量: %d", (int) [myProduct count]);
    // populate UI
    for (SKProduct *product in myProduct) {
//        NSLog(@"product info");
//        NSLog(@"  基本描述: %@", [product description]);
//        NSLog(@"  IAP的id: %@", product.productIdentifier);
//        NSLog(@"  地區(qū)編碼: %@", product.priceLocale.localeIdentifier);
//        NSLog(@"  本地價格: %@", product.price);
//        NSLog(@"  語言代碼: %@", [product.priceLocale objectForKey:NSLocaleLanguageCode]);
//        NSLog(@"  國家代碼: %@", [product.priceLocale objectForKey:NSLocaleCountryCode]);
//        NSLog(@"  貨幣代碼: %@", [product.priceLocale objectForKey:NSLocaleCurrencyCode]);
//        NSLog(@"  貨幣符號: %@", [product.priceLocale objectForKey:NSLocaleCurgegrencySymbol]);
//        NSLog(@"  本地標題: %@", product.localizedTitle);
//        NSLog(@"  本地描述: %@", product.localizedDescription);
        [self updateProductPriceWithId:product.productIdentifier andPrice:product.price];
        if ([[product.priceLocale objectForKey:NSLocaleCurrencyCode] isEqualToString:@"CNY"]) {
            self.CurrencyCode = @"￥";
        } else {
            self.CurrencyCode = [product.priceLocale objectForKey:NSLocaleCurrencySymbol];
        }
    }
    //發(fā)送購買請求
    for (SKProduct *prct in myProduct) {
        if ([self.productsId isEqualToString:prct.productIdentifier]) {
            SKMutablePayment *payment = nil;
            payment = [SKMutablePayment paymentWithProduct:prct];
            payment.quantity = self.quantity;
            [[SKPaymentQueue defaultQueue] addPayment:payment];
        }
    }
}

7. SKPaymentTransactionObserver 此協(xié)議會監(jiān)聽到購買結果,根據(jù)購買結果的不同，做出不同的邏輯。

#pragma mark - SKPaymentTransactionObserver

//----監(jiān)聽購買結果
- (void)paymentQueue:(SKPaymentQueue *)queue updatedTransactions:(NSArray *)transactions {
    //交易結果
    for (SKPaymentTransaction *transaction in transactions) {
        switch (transaction.transactionState) {
            case SKPaymentTransactionStatePurchased: {
                //交易完成
                [self completeTransaction:transaction];
            }
                break;
            case SKPaymentTransactionStateFailed: {
                //交易失敗
                [self hideHud];
                [self failedTransaction:transaction];
                [[ZToastManager ShardInstance] showtoast:@"交易失敗"];
            }
                break;
            case SKPaymentTransactionStateRestored: {
                //已經購買過該商品
                [self hideHud];
                [self restoreTransaction:transaction];
                [[ZToastManager ShardInstance] showtoast:@"已經購買過該商品"];
            }
                break;
            case SKPaymentTransactionStatePurchasing: {
                //商品添加進列表
                NSLog(@"商品添加進列表");
            }
                break;
            case SKPaymentTransactionStateDeferred: {
                NSLog(@"SKPayment Transaction State Deferred");
            }
                break;
            default:
                break;
        }
    }
}

8. 購買成功之后，需將receipt 上傳至自己的服務端

- (void)completeTransaction:(SKPaymentTransaction *)transaction {
    // Your application should implement these two methods.
    //NSString *product = transaction.payment.productIdentifier;
    [self verifyReceipt:transaction];
}