我有一个单 View tvOS应用程序。它具有一个包含24个collectionviewcells的collection View 。选择collectionviewcell后，我会触发警报。我正在使用Apple参考文档中的默认代码(粘贴在下面)。
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];
当我没有将defaultAction添加到警报中时(注释[alert addAction:defaultAction];)，警报将正确显示，但是无法消除它。当我将defaultAction添加到警报中时，该警报显示为“确定”按钮，但在屏幕上出现该消息后便会收到可怕的SIGABRT错误
*** Terminating app due to uncaught exception 'NSInvalidArgumentException',
reason: '-[_UIAlertControllerActionView image]: unrecognized selector
sent to instance 0x7fe571ddee10'
堆栈跟踪在这里:
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
有什么想法吗？？
最佳答案
根据您的堆栈跟踪， View Controller 就是这里的问题:您试图在未实现该方法的对象上调用image方法，这就是导致崩溃的原因。
查看-[ViewController collectionView:didUpdateFocusInContext:withAnimationCoordinator:]的实现，看看在什么地方调用image:看起来您假设该对象属于一种类型，而实际上是另一种。