StoreKit SKProductsRequest崩溃

Question

我使用以下代码根据In-App Purchase Programming Guide请求产品列表。它过去在我的iPhone应用程序中工作得很好，但是现在每次请求产品列表时它都会崩溃。永远不会调用委托方法(void)productsRequest:(SKProductsRequest **)request didReceiveResponse:(SKProductsResponse **)response。

SKProductsRequest *request = [[SKProductsRequest alloc] initWithProductIdentifiers:[NSSet setWithObject:@"my.product.identifier"]];
[request setDelegate:self];
[request start];

正如我所说的，它工作得很好，然后就停止工作了。这是在调用上述代码时发生的崩溃。

Exception Type:  EXC_BAD_ACCESS (SIGBUS)
Exception Codes: KERN_PROTECTION_FAILURE at 0x00000011
Crashed Thread:  0

Thread 0 Crashed:
0   libobjc.A.dylib                 0x000034f8 objc_msgSend + 24
1   StoreKit                        0x00003e18 -[SKProductsRequest handleFinishResponse:returningError:] + 40
2   StoreKit                        0x000050c4 -[SKRequest _requestFinishedNotification:] + 152
3   Foundation                      0x00019b9a _nsnote_callback + 150
4   CoreFoundation                  0x0006c2de __CFXNotificationPost_old + 390
5   CoreFoundation                  0x0001ab32 _CFXNotificationPostNotification + 122
6   Foundation                      0x000048e4 -[NSNotificationCenter postNotificationName:object:userInfo:] + 64
7   AppSupport                      0x0000bb42 -[CPDistributedNotificationCenter deliverNotification:userInfo:] + 38
8   AppSupport                      0x0000cf66 _CPDNDeliverNotification + 198
9   AppSupport                      0x0000ba4a _XDeliverNotification + 110
10  AppSupport                      0x00002e82 migHelperRecievePortCallout + 122
11  CoreFoundation                  0x000742ac __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 22
12  CoreFoundation                  0x000761d6 __CFRunLoopDoSource1 + 158
13  CoreFoundation                  0x0007718e __CFRunLoopRun + 574
14  CoreFoundation                  0x0001e0bc CFRunLoopRunSpecific + 220
15  CoreFoundation                  0x0001dfca CFRunLoopRunInMode + 54
16  GraphicsServices                0x00003f88 GSEventRunModal + 188
17  UIKit                           0x00007b40 -[UIApplication _run] + 564
18  UIKit                           0x00005fb8 UIApplicationMain + 964
19  myapp                           0x00002fae main (main.m:13)
20  myapp                           0x00002f58 start + 32

Thread 1:
0   libSystem.B.dylib               0x00034e84 kevent + 24
1   libSystem.B.dylib               0x00102a48 _dispatch_mgr_invoke + 88
2   libSystem.B.dylib               0x00102494 _dispatch_queue_invoke + 96
3   libSystem.B.dylib               0x00102634 _dispatch_worker_thread2 + 120
4   libSystem.B.dylib               0x0008b53c _pthread_wqthread + 392
5   libSystem.B.dylib               0x00082b6c start_wqthread + 0

Thread 2:
0   libSystem.B.dylib               0x00000ab0 mach_msg_trap + 20
1   libSystem.B.dylib               0x00002f94 mach_msg + 60
2   CoreFoundation                  0x00074b18 __CFRunLoopServiceMachPort + 88
3   CoreFoundation                  0x000770e0 __CFRunLoopRun + 400
4   CoreFoundation                  0x0001e0bc CFRunLoopRunSpecific + 220
5   CoreFoundation                  0x0001dfca CFRunLoopRunInMode + 54
6   WebCore                         0x0000370c RunWebThread(void*) + 552
7   libSystem.B.dylib               0x0008af80 _pthread_start + 364
8   libSystem.B.dylib               0x0007d014 thread_start + 0

Thread 3:
0   libSystem.B.dylib               0x00000ab0 mach_msg_trap + 20
1   libSystem.B.dylib               0x00002f94 mach_msg + 60
2   CoreFoundation                  0x00074b18 __CFRunLoopServiceMachPort + 88
3   CoreFoundation                  0x000770e0 __CFRunLoopRun + 400
4   CoreFoundation                  0x0001e0bc CFRunLoopRunSpecific + 220
5   CoreFoundation                  0x0001dfca CFRunLoopRunInMode + 54
6   Foundation                      0x0003c316 +[NSURLConnection(NSURLConnectionReallyInternal) _resourceLoadLoop:] + 210
7   Foundation                      0x0000c612 -[NSThread main] + 42
8   Foundation                      0x00092140 __NSThread__main__ + 908
9   libSystem.B.dylib               0x0008af80 _pthread_start + 364
10  libSystem.B.dylib               0x0007d014 thread_start + 0

Thread 4:
0   libSystem.B.dylib               0x00029f24 select$DARWIN_EXTSN + 20
1   CoreFoundation                  0x0007aa54 __CFSocketManager + 340
2   libSystem.B.dylib               0x0008af80 _pthread_start + 364
3   libSystem.B.dylib               0x0007d014 thread_start + 0

我不知道是什么导致了objc_msgSend崩溃，也不知道它与StoreKit有什么关系。我也不知道我添加或更改了什么，导致这个简单的代码停止工作。

Answer 1

一个很可能的解释是，您设置为SKProductRequest对象的委托的对象是否已经被释放。

请求很可能需要几秒钟才能完成，这可能会超过您的委托对象的生命周期，因此您可能希望确保它停留足够长的时间。

Answer 2

上面的答案在技术上是正确的，但它并不完整。正如Megastep所说：“您设置为SKProductsRequest委托的对象可能已经被释放了。”因此，您正在向已经释放的对象发送一条消息。现在来看实际的答案：

- (void)requestProUpgradeProductData {
    NSSet *productIdentifiers = //Your Product IDs go here

    productsRequest = [[SKProductsRequest alloc] initWithProductIdentifiers:productIdentifiers];
    productsRequest.delegate = self;
    [productsRequest start];

    // we will release the request object in the delegate callback
}

#pragma mark -
#pragma mark SKProductRequest Delegate Methods

- (void)productsRequest:(SKProductsRequest *)request didReceiveResponse(SKProductsResponse *)response {
self.products = response.products;
//NSLog(@"%i",[products count]);
proUpgradeProduct = [products count] == 4 ? [[products objectAtIndex:0] retain] : nil;
if (proUpgradeProduct)
{
    //Do your stuff here...
}

for (NSString *invalidProductId in response.invalidProductIdentifiers)
{
    //NSLog(@"Invalid product id: %@" , invalidProductId);
}

// finally release the reqest we alloc/init’ed in requestProUpgradeProductData
[productsRequest release];

[[NSNotificationCenter defaultCenter] postNotificationName:kInAppPurchaseManagerProductsFetchedNotification object:self userInfo:nil];
}

基本上，正如你在上面看到的，你不需要释放productsRequest，因为它已经在委托回调方法中被释放了。同样，您不需要在viewDidUnload/dealloc方法中调用productsRequest release或将其设置为Nil，因为如果在调用回调方法之前关闭视图，这可能会导致崩溃。

Answer 3

我正在使用一个类似于委托的对象。因此，在这个对象的deinit方法中，我删除了委托a，并修复了崩溃问题。

private var currentProductRequest: SKProductsRequest?

deinit {
    if let r = currentProductRequest {
        r.delegate = nil
        r.cancel()
        currentProductRequest = nil
    }
}