ios 内购

首先要引入#import <StoreKit/StoreKit.h>
本文介绍的是有服务器的情况下，已经从服务器获取到了productId

#import <StoreKit/StoreKit.h>
#import "IapManager.h"

@implementation IapManager {
    NSMutableDictionary *products;
}

static IapManager *_instance;

+ (IapManager *)instance {
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        _instance = [[IapManager alloc] init];
    });
    
    return _instance;
}

- (id) init {
    self = [super init];

    products = [[NSMutableDictionary alloc] init];
    return self;
}

/**
* productId: 已经从服务器获取到了productId
* outTradeNo: 服务器自己构建的校验订单
*/
+ (void)iapPay:(NSString *)productId
    outTradeNo:(NSString *)outTradeNo {
    [[IapManager instance] iapPay:productId
                       outTradeNo:outTradeNo];
}

/**
 * 执行实际的支付逻辑
 */
- (void)iapPay:(NSString *)productId
    outTradeNo:(NSString *)outTradeNo {
    
    if (productId == nil || outTradeNo == nil) {
        NSLog(@"iap pay fail, invalid parameter.");
        // 此处应该通知客户端
        return;
    }
    
    if (![SKPaymentQueue canMakePayments]) {
        NSLog(@"iap pay fail, can not make payments.");
        NSLog(@"失败，用户禁止应用内付费购买.");
        // 此处应该通知客户端
        return;
    }
    
    SKProduct *product = nil;
    @synchronized (self) {
        product = products[productId];
    }
    
    if (product == nil) {
        NSLog(@"iap pay fail, no product info.");
        // 此处应该通知客户端
        return;
    }
    
    NSLog(@"iap start payment -> {productId:%@, outTradeNo:%@}",
          productId,
          outTradeNo);
    
    SKMutablePayment *payment = [SKMutablePayment paymentWithProduct:product];
    payment.quantity = 1;
    payment.applicationUsername = outTradeNo;
    [[SKPaymentQueue defaultQueue] addPayment:payment];
     NSLog(@"iap inprogress.");
}

/**
 * 监听Iap交易的状态
 */
- (void)paymentQueue:(SKPaymentQueue *)queue
 updatedTransactions:(NSArray *)transactions {
    NSLog(@"监听Iap交易的状态");
   
    for (SKPaymentTransaction *trans in transactions) {
        NSLog(@"%d",trans.error.code);

        switch (trans.transactionState) {
            case SKPaymentTransactionStatePurchased:
                     NSLog(@"交易ok");
                [self transactionSuccess:trans];
                break;
                
            case SKPaymentTransactionStatePurchasing:
                 NSLog(@"交易中");
                //[self transactionAbort:trans];
                // 正在支付中这个状态，会在刚刚发起支付，弹出用户名密码对话框的时候调用一次。
                break;
                
            case SKPaymentTransactionStateFailed:
                [self transactionFail:trans];
                break;
                
            case SKPaymentTransactionStateDeferred:
                     NSLog(@"交易deferred");
                // 这个状态应该是在出现家长监护的时候出现。
                break;
                
            case SKPaymentTransactionStateRestored:
                // 不存在不同设备间恢复的问题，因此直接结束当前的订单。
                [self transactionFinish:trans];
                break;
                
            default:
                // 不知名情况的订单，也直接结束掉。
                [self transactionFinish:trans];
                break;
        }
    }
}

/**
 * 交易成功。
 */
- (void)transactionSuccess:(SKPaymentTransaction *)trans {
    NSLog(@"交易成功");
    if (trans == nil) {
        return;
    }
    
    NSURL *receiptUrl = [[NSBundle mainBundle] appStoreReceiptURL];
    NSData *receipt = [NSData dataWithContentsOfURL:receiptUrl];
    NSString *receiptDataString = [receipt base64EncodedStringWithOptions:0];
    
    NSString *outTradeNo = trans.payment.applicationUsername;
    NSString *productId = trans.payment.productIdentifier;
 
    NSLog(@"注意transactionIdentifier %@",trans.transactionIdentifier);
    NSLog(@"iap pay success. productId:%@, outTradeNo:%@, receipt:%@",
          productId,
          outTradeNo,
          receiptDataString);
 
   // 此处应该通知客户端
    [[SKPaymentQueue defaultQueue] finishTransaction:trans];
}

/**
 * 交易失败
 */
- (void)transactionFail:(SKPaymentTransaction *)trans {
    NSLog(@"交易失败");
    if (trans == nil) {
        return;
    }
    
    NSString *outTradeNo = trans.payment.applicationUsername;
    NSString *productId = trans.payment.productIdentifier;
    
    NSLog(@"iap pay fail. productId:%@, outTradeNo:%@",
          productId,
          outTradeNo);

    // 此处应该通知客户端
    [[SKPaymentQueue defaultQueue] finishTransaction:trans];
}

/**
 * 交易完成
 */
- (void)transactionFinish:(SKPaymentTransaction *)trans {
    NSLog(@"交易结束");
    if (trans == nil) {
        return;
    }
    
    NSString *outTradeNo = trans.payment.applicationUsername;
    NSString *productId = trans.payment.productIdentifier;
    
    NSLog(@"iap pay finish. productId:%@, outTradeNo:%@",
          productId,
          outTradeNo);
   
    [[SKPaymentQueue defaultQueue] finishTransaction:trans];
}