Yesterday I have met one annoying problem: after I have set up IAP (Inner App Purchase ),
I try to do the test, when I purchase the first time, it is no problem at all, but if I back to the main window from the subview, and then enter subview to purchase again, the App crashed.
The following is the screen shot:
I have tried many times to locate the problem, and I have found it always after I have back to superview and enter subview, the problem always stop at: [[SKPaymentQueue defaultQueue] addPayment:payment];
Then I searched it in google, and have found the same problem in stackoverflow.com
http://stackoverflow.com/questions/11170614/viewcontroller-respondstoselector-message-sent-to-deallocated-instance-crash
this article said the crash reason is "The crash occurs when that controller was dealloc‘ed but was still the delegate for the view controller.”
according to this article, i have added some codes below:
-(void) viewWillDisappear:(BOOL) animated
{
[super viewWillDisappear:animated];
if ([self isMovingFromParentViewController])
{
if (productsRequest.delegate == self)
{
productsRequest.delegate = nil;
}
}
}
but the problem still there!
Then I thought it should related with dealloc , because "message sent to deallocated instance”. so I search method -(void)dealloc , the method is already there , came from init view controller, there is some description of “we need to manually stop observing any NSNotificationCenter notifications. Otherwise we could get "zombie" crashes”. And then I have found I add one observer in “view did load", but I have not removed it after view controller deallocated.
-(void)viewDidLoad
{
[[SKPaymentQueue defaultQueue] addTransactionObserver:self]; object:nil];
}
After I have removed Transaction Observer in dealloc , then the problem solved.
-(void)dealloc
{
[[SKPaymentQueue defaultQueue] removeTransactionObserver:self];
}
[HelpViewController respondsToSelector] message sent to deallocated instance
原文：http://www.cnblogs.com/myblog-12368/p/4367034.html