我无法理解Apple的崩溃日志。因为这个原因，我被拒绝了几次。他们抱怨说它发生在运行最新软件10.3.1的ipad上。当我们在ipad模拟器上仔细检查时，它会在没有崩溃的情况下运行。
Last Exception Backtrace:
0 CoreFoundation 0x1848b2fd8 __exceptionPreprocess + 124
1 libobjc.A.dylib 0x183314538 objc_exception_throw + 56
2 CoreFoundation 0x1848b2eac +[NSException raise:format:arguments:] + 104
3 Foundation 0x18534a710 -[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:] + 112
4 UIKit 0x18ac57454 -[UIApplication _cachedSystemAnimationFenceCreatingIfNecessary:] + 196
5 UIKit 0x18ac57514 -[UIApplication _systemAnimationFenceCreatingIfNecessary:] + 24
6 UIKit 0x18acb07a0 +[UIWindow _synchronizedDrawingFence] + 116
7 UIKit 0x18ae6e150 +[_UIKeyboardChangedInformation informationForKeyboardUp:withIAV:] + 104
8 UIKit 0x18b1678d4 -[_UIRemoteKeyboards prepareToMoveKeyboard:withIAV:showing:forScreen:] + 464
9 UIKit 0x18aa9fc04 -[UIPeripheralHost(UIKitInternal) setInputViews:animationStyle:] + 820
10 UIKit 0x18aabccf4 -[UIPeripheralHost(UIKitInternal) _restoreInputViewsWithId:animated:] + 584
11 UIKit 0x18ad4fd64 -[UIViewController _restoreInputViewsForPresentation] + 280
12 UIKit 0x18ad2ae3c -[UIPresentationController runTransitionForCurrentState] + 1560
13 UIKit 0x18ad290f8 -[UIPresentationController _dismissWithAnimationController:interactionController:target:didEndSelector:] + 764
14 UIKit 0x18ad4f8c0 -[UIViewController _dismissViewControllerWithAnimationController:interactionController:completion:] + 464
15 UIKit 0x18ab04cd4 -[UIViewController _dismissViewControllerWithTransition:from:completion:] + 600
16 UIKit 0x18aaacb6c -[UIViewController dismissViewControllerWithTransition:completion:] + 1144
17 UIKit 0x18aaac94c -[UIViewController dismissViewControllerWithTransition:completion:] + 600
18 UIKit 0x18ad4eb68 -[UIViewController _performCoordinatedPresentOrDismiss:animated:] + 524
19 UIKit 0x18aaac6c0 -[UIViewController dismissViewControllerAnimated:completion:] + 152
20 newapp 0x100115628 0x1000b0000 + 415272
21 newapp 0x1001159e8 0x1000b0000 + 416232
22 CFNetwork 0x184ebc1fc __75-[__NSURLSessionLocal taskForClass:request:uploadFile:bodyData:completion:]_block_invoke + 32
23 CFNetwork 0x184ed3ef8 __49-[__NSCFLocalSessionTask _task_onqueue_didFinish]_block_invoke + 148
24 Foundation 0x185381804 __NSBLOCKOPERATION_IS_CALLING_OUT_TO_A_BLOCK__ + 16
25 Foundation 0x1852c6760 -[NSBlockOperation main] + 96
26 Foundation 0x1852b6b18 -[__NSOperationInternal _start:] + 612
27 Foundation 0x185383ba0 __NSOQSchedule_f + 228
28 libdispatch.dylib 0x18376a9a0 _dispatch_client_callout + 16
29 libdispatch.dylib 0x183778ad4 _dispatch_queue_serial_drain + 928
30 libdispatch.dylib 0x18376e2cc _dispatch_queue_invoke + 884
31 libdispatch.dylib 0x18377aa50 _dispatch_root_queue_drain + 540
32 libdispatch.dylib 0x18377a7d0 _dispatch_worker_thread3 + 124
33 libsystem_pthread.dylib 0x1839731d0 _pthread_wqthread + 1096
34 libsystem_pthread.dylib 0x183972d7c start_wqthread + 4
Thread 0 name: Dispatch queue: com.apple.main-thread
Thread 0:
0 libsystem_kernel.dylib 0x000000018388f224 mach_msg_trap + 8
1 libsystem_kernel.dylib 0x000000018388f09c mach_msg + 72
2 CoreFoundation 0x0000000184860e88 __CFRunLoopServiceMachPort + 192
3 CoreFoundation 0x000000018485eadc __CFRunLoopRun + 1060
4 CoreFoundation 0x000000018478ed94 CFRunLoopRunSpecific + 424
5 GraphicsServices 0x00000001861f8074 GSEventRunModal + 100
6 UIKit 0x000000018aa40130 UIApplicationMain + 208
7 newapp 0x000000010022f390 0x1000b0000 + 1569680
8 libdyld.dylib 0x000000018379d59c start + 4
Thread 1 name: com.apple.uikit.eventfetch-thread
Thread 1:
0 libsystem_kernel.dylib 0x000000018388f224 mach_msg_trap + 8
1 libsystem_kernel.dylib 0x000000018388f09c mach_msg + 72
2 CoreFoundation 0x0000000184860e88 __CFRunLoopServiceMachPort + 192
3 CoreFoundation 0x000000018485eadc __CFRunLoopRun + 1060
4 CoreFoundation 0x000000018478ed94 CFRunLoopRunSpecific + 424
5 Foundation 0x00000001852a8d64 -[NSRunLoop(NSRunLoop) runMode:beforeDate:] + 304
6 Foundation 0x00000001852c9b34 -[NSRunLoop(NSRunLoop) runUntilDate:] + 96
7 UIKit 0x000000018b3ca5f8 -[UIEventFetcher threadMain] + 136
8 Foundation 0x00000001853a62c8 __NSThread__start__ + 996
9 libsystem_pthread.dylib 0x000000018397575c _pthread_body + 240
10 libsystem_pthread.dylib 0x000000018397566c _pthread_body + 0
11 libsystem_pthread.dylib 0x0000000183972d84 thread_start + 4
Thread 2:
0 libsystem_kernel.dylib 0x00000001838ada88 __workq_kernreturn + 8
1 libsystem_pthread.dylib 0x0000000183973274 _pthread_wqthread + 1260
2 libsystem_pthread.dylib 0x0000000183972d7c start_wqthread + 4
Thread 3 name: com.apple.CFStream.LegacyThread
Thread 3:
0 libsystem_kernel.dylib 0x000000018388f224 mach_msg_trap + 8
1 libsystem_kernel.dylib 0x000000018388f09c mach_msg + 72
2 CoreFoundation 0x0000000184860e88 __CFRunLoopServiceMachPort + 192
3 CoreFoundation 0x000000018485eadc __CFRunLoopRun + 1060
4 CoreFoundation 0x000000018478ed94 CFRunLoopRunSpecific + 424
5 CoreFoundation 0x000000018486e78c _legacyStreamRunLoop_workThread + 268
6 libsystem_pthread.dylib 0x000000018397575c _pthread_body + 240
7 libsystem_pthread.dylib 0x000000018397566c _pthread_body + 0
8 libsystem_pthread.dylib 0x0000000183972d84 thread_start + 4
Thread 4 name: com.apple.NSURLConnectionLoader
Thread 4:
0 libsystem_kernel.dylib 0x000000018388f224 mach_msg_trap + 8
1 libsystem_kernel.dylib 0x000000018388f09c mach_msg + 72
2 CoreFoundation 0x0000000184860e88 __CFRunLoopServiceMachPort + 192
3 CoreFoundation 0x000000018485eadc __CFRunLoopRun + 1060
4 CoreFoundation 0x000000018478ed94 CFRunLoopRunSpecific + 424
5 CFNetwork 0x0000000184f9aca4 +[NSURLConnection(Loader) _resourceLoadLoop:] + 404
6 Foundation 0x00000001853a62c8 __NSThread__start__ + 996
7 libsystem_pthread.dylib 0x000000018397575c _pthread_body + 240
8 libsystem_pthread.dylib 0x000000018397566c _pthread_body + 0
9 libsystem_pthread.dylib 0x0000000183972d84 thread_start + 4
Thread 5 name: Dispatch queue: NSOperationQueue 0x170031360 :: NSOperation 0x17024ab30 (QOS: DEFAULT)
Thread 5 Crashed:
0 libsystem_kernel.dylib 0x00000001838ad014 __pthread_kill + 8
1 libsystem_pthread.dylib 0x0000000183977334 pthread_kill + 112
2 libsystem_c.dylib 0x00000001838219c4 abort + 140
3 libc++abi.dylib 0x00000001832ed1b0 __cxa_bad_cast + 0
4 libc++abi.dylib 0x0000000183306c04 default_unexpected_handler() + 0
5 libobjc.A.dylib 0x0000000183314820 _objc_terminate() + 124
6 libc++abi.dylib 0x00000001833035d4 std::__terminate(void (*)()) + 16
7 libc++abi.dylib 0x0000000183303640 std::terminate() + 60
8 libdispatch.dylib 0x000000018376a9b4 _dispatch_client_callout + 36
9 libdispatch.dylib 0x0000000183778ad4 _dispatch_queue_serial_drain + 928
10 libdispatch.dylib 0x000000018376e2cc _dispatch_queue_invoke + 884
11 libdispatch.dylib 0x000000018377aa50 _dispatch_root_queue_drain + 540
12 libdispatch.dylib 0x000000018377a7d0 _dispatch_worker_thread3 + 124
13 libsystem_pthread.dylib 0x00000001839731d0 _pthread_wqthread + 1096
14 libsystem_pthread.dylib 0x0000000183972d7c start_wqthread + 4
答案 0 :(得分：3)
日志清楚地显示问题发生在后台线程上。您需要在主队列上执行UI操作。使用DispatchQueue.main.async关闭视图控制器。