我们的应用程序在iOS 7中崩溃，它在iOS 6中运行良好。我们不确定是什么导致了这个问题。我们可以看到抛出了一些异常，但是我们不确定代码在哪里导致这种情况。
以下是崩溃报告：
Incident Identifier: 1F589930-15BD-49F7-80E6-831A95092FDF
CrashReporter Key: aaa79870161ff1e371394b881a26e97f0066f464
Hardware Model: iPhone5,2
Process: myapp [1492]
Path: /var/mobile/Applications/A121DF2F-A7B9-4DD9-9FBC-BB06CD7C5EF5/myapp.app/myapp
Identifier: co.uk.myapp
Version: 1.0 (0.9)
Code Type: ARM (Native)
Parent Process: launchd [1]
Date/Time: 2013-10-01 14:59:17.555 +0530
OS Version: iOS 7.0 (11A465)
Report Version: 104
Exception Type: EXC_CRASH (SIGABRT)
Exception Codes: 0x0000000000000000, 0x0000000000000000
Triggered by Thread: 2
Last Exception Backtrace:
0 CoreFoundation 0x2d4e4e86 __exceptionPreprocess + 126
1 libobjc.A.dylib 0x377de6c2 objc_exception_throw + 34
2 CoreFoundation 0x2d41e0c6 -[__NSPlaceholderArray initWithObjects:count:] + 414
3 CoreFoundation 0x2d427a4c +[NSArray arrayWithObjects:count:] + 40
4 CoreFoundation 0x2d45d9c0 -[NSDictionary allKeys] + 172
5 Foundation 0x2df73336 -[NSISObjectiveLinearExpression description] + 122
6 Foundation 0x2ddfc808 _NSDescriptionWithLocaleFunc + 84
7 CoreFoundation 0x2d4babf2 __CFStringAppendFormatCore + 5618
8 CoreFoundation 0x2d429d18 _CFStringCreateWithFormatAndArgumentsAux + 72
9 CoreFoundation 0x2d4523c2 _CFLogvEx + 82
10 Foundation 0x2de0b7ee NSLogv + 82
11 Foundation 0x2de0b78e NSLog + 22
12 Foundation 0x2de4a918 -[NSISEngine minimizeConstantInObjectiveRowWithHead:] + 180
13 Foundation 0x2de4a46e -[NSISEngine optimize] + 170
14 Foundation 0x2de461a8 -[NSISEngine withBehaviors:performModifications:] + 312
15 UIKit 0x2fc69490 -[UIView(Hierarchy) _postMovedFromSuperview:] + 292
16 UIKit 0x2feffb92 __UIViewWasRemovedFromSuperview + 214
17 UIKit 0x2fc68342 -[UIView(Hierarchy) removeFromSuperview] + 266
18 UIKit 0x2fd3cccc -[UIScrollView removeFromSuperview] + 60
19 UIKit 0x2fd313e4 -[UINavigationController navigationTransitionView:didEndTransition:fromView:toView:] + 312
20 UIKit 0x2fdfcb5c __49-[UINavigationController _startCustomTransition:]_block_invoke + 156
21 UIKit 0x2fd81416 -[_UIViewControllerTransitionContext completeTransition:] + 70
22 UIKit 0x2fe418dc __53-[_UINavigationParallaxTransition animateTransition:]_block_invoke105 + 448
23 UIKit 0x2fca2618 -[UIViewAnimationBlockDelegate _didEndBlockAnimation:finished:context:] + 280
24 UIKit 0x2fca226a -[UIViewAnimationState sendDelegateAnimationDidStop:finished:] + 174
25 UIKit 0x2fca2186 -[UIViewAnimationState animationDidStop:finished:] + 62
26 QuartzCore 0x2f8f8a0e CA::Layer::run_animation_callbacks(void*) + 230
27 libdispatch.dylib 0x37cc30ea _dispatch_client_callout + 18
28 libdispatch.dylib 0x37cc59a4 _dispatch_main_queue_callback_4CF + 264
29 CoreFoundation 0x2d4af5b4 __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 4
30 CoreFoundation 0x2d4ade80 __CFRunLoopRun + 1304
31 CoreFoundation 0x2d41853c CFRunLoopRunSpecific + 520
32 CoreFoundation 0x2d41831e CFRunLoopRunInMode + 102
33 GraphicsServices 0x3214f2e6 GSEventRunModal + 134
34 UIKit 0x2fccf1e0 UIApplicationMain + 1132
35 myapp 0x00020a16 main (main.mm:16)
36 libdyld.dylib 0x37cd7ab2 tlv_initializer + 2
Thread 0:
0 libsystem_kernel.dylib 0x37d8e588 __semwait_signal_nocancel + 24
1 libsystem_c.dylib 0x37d09788 nanosleep$NOCANCEL + 160
2 libsystem_c.dylib 0x37d24f10 usleep$NOCANCEL + 48
3 libsystem_c.dylib 0x37d3f030 abort + 80
4 myapp 0x001efaea uncaught_exception_handler + 22
5 CoreFoundation 0x2d4e518a __handleUncaughtException + 578
6 libobjc.A.dylib 0x377de924 _objc_terminate() + 172
7 libc++abi.dylib 0x371a51b0 std::__terminate(void (*)()) + 76
8 libc++abi.dylib 0x371a4a04 __cxa_throw + 112
9 libobjc.A.dylib 0x377de796 objc_exception_throw + 246
10 CoreFoundation 0x2d41e0c6 -[__NSPlaceholderArray initWithObjects:count:] + 414
11 CoreFoundation 0x2d427a4c +[NSArray arrayWithObjects:count:] + 40
12 CoreFoundation 0x2d45d9c0 -[NSDictionary allKeys] + 172
13 Foundation 0x2df73336 -[NSISObjectiveLinearExpression description] + 122
14 Foundation 0x2ddfc808 _NSDescriptionWithLocaleFunc + 84
15 CoreFoundation 0x2d4babf4 __CFStringAppendFormatCore + 5620
16 CoreFoundation 0x2d429d18 _CFStringCreateWithFormatAndArgumentsAux + 72
17 CoreFoundation 0x2d4523c2 _CFLogvEx + 82
18 Foundation 0x2de0b7ee NSLogv + 82
19 Foundation 0x2de0b78e NSLog + 22
20 Foundation 0x2de4a918 -[NSISEngine minimizeConstantInObjectiveRowWithHead:] + 180
21 Foundation 0x2de4a46e -[NSISEngine optimize] + 170
22 Foundation 0x2de461a8 -[NSISEngine withBehaviors:performModifications:] + 312
23 UIKit 0x2fc69490 -[UIView(Hierarchy) _postMovedFromSuperview:] + 292
24 UIKit 0x2feffb92 __UIViewWasRemovedFromSuperview + 214
25 UIKit 0x2fc68342 -[UIView(Hierarchy) removeFromSuperview] + 266
26 UIKit 0x2fd3cccc -[UIScrollView removeFromSuperview] + 60
27 UIKit 0x2fd313e4 -[UINavigationController navigationTransitionView:didEndTransition:fromView:toView:] + 312
28 UIKit 0x2fdfcb5c __49-[UINavigationController _startCustomTransition:]_block_invoke + 156
29 UIKit 0x2fd81418 -[_UIViewControllerTransitionContext completeTransition:] + 72
30 UIKit 0x2fe418dc __53-[_UINavigationParallaxTransition animateTransition:]_block_invoke105 + 448
31 UIKit 0x2fca261a -[UIViewAnimationBlockDelegate _didEndBlockAnimation:finished:context:] + 282
32 UIKit 0x2fca226a -[UIViewAnimationState sendDelegateAnimationDidStop:finished:] + 174
33 UIKit 0x2fca2186 -[UIViewAnimationState animationDidStop:finished:] + 62
34 QuartzCore 0x2f8f8a0e CA::Layer::run_animation_callbacks(void*) + 230
35 libdispatch.dylib 0x37cc30ec _dispatch_client_callout + 20
36 libdispatch.dylib 0x37cc59a4 _dispatch_main_queue_callback_4CF + 264
37 CoreFoundation 0x2d4af5b4 __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 4
38 CoreFoundation 0x2d4ade80 __CFRunLoopRun + 1304
39 CoreFoundation 0x2d41853c CFRunLoopRunSpecific + 520
40 CoreFoundation 0x2d41831e CFRunLoopRunInMode + 102
41 GraphicsServices 0x3214f2e6 GSEventRunModal + 134
42 UIKit 0x2fccf1e0 UIApplicationMain + 1132
43 myapp 0x00020a16 main (main.mm:16)
44 libdyld.dylib 0x37cd7ab4 start + 0
Thread 1:
0 libsystem_kernel.dylib 0x37d7b838 kevent64 + 24
1 libdispatch.dylib 0x37cca0d0 _dispatch_mgr_invoke + 228
2 libdispatch.dylib 0x37cc463e _dispatch_mgr_thread + 34
Thread 2 Crashed:
0 libsystem_kernel.dylib 0x37d8ec7c __workq_kernreturn + 8
1 libsystem_pthread.dylib 0x37df2e06 _pthread_wqthread + 306
2 libsystem_pthread.dylib 0x37df2cc0 start_wqthread + 4
Thread 3 name: com.apple.NSURLConnectionLoader
Thread 3:
0 libsystem_kernel.dylib 0x37d7ba84 mach_msg_trap + 20
1 libsystem_kernel.dylib 0x37d7b87c mach_msg + 36
2 CoreFoundation 0x2d4af55c __CFRunLoopServiceMachPort + 152
3 CoreFoundation 0x2d4adc7c __CFRunLoopRun + 788
4 CoreFoundation 0x2d41853c CFRunLoopRunSpecific + 520
5 CoreFoundation 0x2d41831e CFRunLoopRunInMode + 102
6 Foundation 0x2de5364c +[NSURLConnection(Loader) _resourceLoadLoop:] + 316
7 Foundation 0x2dec8dc2 __NSThread__main__ + 1058
8 libsystem_pthread.dylib 0x37df4c5a _pthread_body + 138
9 libsystem_pthread.dylib 0x37df4bca _pthread_start + 98
10 libsystem_pthread.dylib 0x37df2ccc thread_start + 4
Thread 4:
0 libsystem_kernel.dylib 0x37d7ba84 mach_msg_trap + 20
1 libsystem_kernel.dylib 0x37d7b87c mach_msg + 36
2 CoreFoundation 0x2d4af55c __CFRunLoopServiceMachPort + 152
3 CoreFoundation 0x2d4adc7c __CFRunLoopRun + 788
4 CoreFoundation 0x2d41853c CFRunLoopRunSpecific + 520
5 CoreFoundation 0x2d41831e CFRunLoopRunInMode + 102
6 Foundation 0x2de06822 -[NSRunLoop(NSRunLoop) runMode:beforeDate:] + 250
7 Foundation 0x2de57664 -[NSRunLoop(NSRunLoop) run] + 76
8 myapp 0x001c1ffa +[AFURLConnectionOperation networkRequestThreadEntryPoint:] (AFURLConnectionOperation.m:160)
9 Foundation 0x2dec8dc2 __NSThread__main__ + 1058
10 libsystem_pthread.dylib 0x37df4c5a _pthread_body + 138
11 libsystem_pthread.dylib 0x37df4bca _pthread_start + 98
12 libsystem_pthread.dylib 0x37df2ccc thread_start + 4
Thread 5 name: com.apple.CFSocket.private
Thread 5:
0 libsystem_kernel.dylib 0x37d8e440 select$DARWIN_EXTSN + 20
1 CoreFoundation 0x2d4b345e __CFSocketManager + 482
2 libsystem_pthread.dylib 0x37df4c5a _pthread_body + 138
3 libsystem_pthread.dylib 0x37df4bca _pthread_start + 98
4 libsystem_pthread.dylib 0x37df2ccc thread_start + 4
Thread 6:
0 libsystem_kernel.dylib 0x37d8ec7c __workq_kernreturn + 8
1 libsystem_pthread.dylib 0x37df2e06 _pthread_wqthread + 306
2 libsystem_pthread.dylib 0x37df2cc0 start_wqthread + 4
Thread 2 crashed with ARM Thread State (32-bit):
r0: 0x00000004 r1: 0x00000000 r2: 0x00000000 r3: 0x00000000
r4: 0x02bcc000 r5: 0x00060001 r6: 0x00004007 r7: 0x02bcbfe0
r8: 0x00000000 r9: 0x00000001 r10: 0x00000000 r11: 0x00000000
ip: 0x00000170 sp: 0x02bcbfc8 lr: 0x37df2e0b pc: 0x37d8ec7c
cpsr: 0x40000010
答案 0 :(得分：7)
这次崩溃看起来像你在app中设置的约束（在后台线程中？）。
此外，这与您报告的其他崩溃类似（不完全相同）：https://stackoverflow.com/questions/19114389/app-hang-and-then-crash-ios-7
简而言之：您的约束设置（可能在代码中）会导致此问题。很可能是因为您的约束引用了不再存在的视图。
长期：
从线程2中，一些代码被分派到主线程中：
28 libdispatch.dylib 0x37cc59a4 _dispatch_main_queue_callback_4CF + 264
通过导航控制器转换到另一个View Controller确实完成了：
21 UIKit 0x2fd81416 -[_UIViewControllerTransitionContext completeTransition:] + 70
正在从其超级视图中删除滚动视图：
18 UIKit 0x2fd3cccc -[UIScrollView removeFromSuperview] + 60
正在评估约束：
12 Foundation 0x2de4a918 -[NSISEngine minimizeConstantInObjectiveRowWithHead:] + 180
约束引擎想要将一些错误记录到控制台中：
11 Foundation 0x2de0b78e NSLog + 22
约束引擎尝试生成字符串：
5 Foundation 0x2df73336 -[NSISObjectiveLinearExpression description] + 122
发生异常是因为它尝试将nil对象添加到NSArray。
如果您的约束规则（在代码中完成）引用另一个不再存在的视图，则可能会发生这种情况。您应该检查约束规则并设置断点以找出导致崩溃的那个。