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objective-ccrashuialertcontrollertvosuialertaction

tvOS app - UIAlertController crashes with UIAlertAction


I have a single view tvOS app. It has a collection view with 24 collectionviewcells. When a collectionviewcell is selected, I trigger an alert. I am using the default code from Apple's reference docs (pasted below).

 UIAlertController* alert = [UIAlertController alertControllerWithTitle:@"My Alert"
                                               message:@"This is an alert."
                                               preferredStyle:UIAlertControllerStyleAlert];

 UIAlertAction* defaultAction = [UIAlertAction actionWithTitle:@"OK" 
                                               style:UIAlertActionStyleDefault
                                               handler:^(UIAlertAction * action) {}];

[alert addAction:defaultAction]; // This is what I comment out
[self presentViewController:alert animated:YES completion:nil];

When I do not add the defaultAction to the alert (comment out [alert addAction:defaultAction];), the alert displays properly but no way to dismiss it. When I add defaultAction to the alert, the alert displays with the 'OK' button, but get the dreaded SIGABRT error as soon as it appears on screen

*** Terminating app due to uncaught exception 'NSInvalidArgumentException', 
reason: '-[_UIAlertControllerActionView image]: unrecognized selector
 sent to instance 0x7fe571ddee10'

Stack trace here:

2015-11-10 19:42:02.927 AppABC[1701:97632] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[_UIAlertControllerActionView image]: unrecognized selector sent to instance 0x7fefd3ddaf10'
*** First throw call stack:
(
0   CoreFoundation                      0x000000010de0a0b5 __exceptionPreprocess + 165
1   libobjc.A.dylib                     0x000000010d884deb objc_exception_throw + 48
2   CoreFoundation                      0x000000010de126dd -[NSObject(NSObject) doesNotRecognizeSelector:] + 205
3   CoreFoundation                      0x000000010dd6005a ___forwarding___ + 970
4   CoreFoundation                      0x000000010dd5fc08 _CF_forwarding_prep_0 + 120
5   IsItGood                            0x000000010d381170 __82-[ViewController collectionView:didUpdateFocusInContext:withAnimationCoordinator:]_block_invoke78 + 48
6   UIKit                               0x000000010e260df4 +[UIView(UIViewAnimationWithBlocks) _setupAnimationWithDuration:delay:view:options:factory:animations:start:animationStateGenerator:completion:] + 582
7   UIKit                               0x000000010e2612ec +[UIView(UIViewAnimationWithBlocks) animateWithDuration:animations:] + 63
8   IsItGood                            0x000000010d380ca8 -[ViewController collectionView:didUpdateFocusInContext:withAnimationCoordinator:] + 536
9   UIKit                               0x000000010ea24e09 -[UICollectionView _didUpdateFocusInContext:withAnimationCoordinator:] + 1181
10  UIKit                               0x000000010eb15a5e _UIFocusEnvironmentDidUpdateFocus + 628
11  UIKit                               0x000000010e4fe102 __36-[UIScreen _updateFocusWithContext:]_block_invoke + 88
12  UIKit                               0x000000010e4fe161 __36-[UIScreen _updateFocusWithContext:]_block_invoke + 183
13  UIKit                               0x000000010e4fdb9f -[UIScreen _updateFocusWithContext:] + 1912
14  UIKit                               0x000000010e4feca9 -[UIScreen updateFocusIfNeeded] + 597
15  UIKit                               0x000000010e1c1e4a _runAfterCACommitDeferredBlocks + 317
16  UIKit                               0x000000010e1d53d9 _cleanUpAfterCAFlushAndRunDeferredBlocks + 95
17  UIKit                               0x000000010e1e1312 _afterCACommitHandler + 90
18  CoreFoundation                      0x000000010dd35ab7 __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 23
19  CoreFoundation                      0x000000010dd35a27 __CFRunLoopDoObservers + 391
20  CoreFoundation                      0x000000010dd2b67b __CFRunLoopRun + 1147
21  CoreFoundation                      0x000000010dd2af78 CFRunLoopRunSpecific + 488
22  GraphicsServices                    0x0000000111582ad2 GSEventRunModal + 161
23  UIKit                               0x000000010e1b608d UIApplicationMain + 171
24  AppABC                              0x000000010d3826af main + 111
25  libdyld.dylib                       0x000000011050d9e9 start + 1
26  ???                                 0x0000000000000001 0x0 + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException

Any thoughts??


Solution

  • Based on your stack trace, your view controller is the problem here: you're trying to call the image method on something that doesn't implement that method, which is what causes this crash.

    Look at your implementation of -[ViewController collectionView:didUpdateFocusInContext:withAnimationCoordinator:] and see where you're calling image on something: it look like you're assuming that object is of one type, when in reality it's another.