如果您曾经问过我如何在 Objective-c 中调试发布/分配问题，您会遇到这些有助于追踪问题的环境设置：
NSZombieEnabled- 发布后保留下流，所以你可以得到指针等。MallocStackLogging- 保留对象历史以供以后参考NSDebugEnabled
您将所有这些设置为YES在“可执行文件”（在组树中找到）信息的“参数”选项卡的“环境”部分中。
所以，我得到这个控制台输出
MyApp [ 4413 :40b]-[CALayer retainCount]：消息发送到已释放实例0x4dbb170
然后打开终端，而调试器已转发中断并键入：
malloc_history 4413 0x4dbb170
然后，我得到一个大文本转储，据我了解，重要的是：
1
ALLOC 0x4dbb160-0x4dbb171 [size=18]:
thread_a0375540 |start | main |
UIApplicationMain | GSEventRun |
GSEventRunModal | CFRunLoopRunInMode |
CFRunLoopRunSpecific | __CFRunLoopRun
| __CFRunLoopDoTimer |
__CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__
| __NSFireDelayedPerform |
-[todoListViewController drillDocumentMenu:] |
-[documentListViewController drillIntoDocumentWithToDoRecord:] |
-[documentViewController OpenTodoDocument:OfType:WithPath:] |
-[documentViewController OpenDocumentOfType:WithPath:] |
-[documentViewController managePDFDocumentWithPath:] |
-[PDFDocument loadPDFDocumentWithPath:andTitle:] |
-[PDFDocument getMetaData] | CGPDFDictionaryApplyFunction |
ListDictionaryObjects(char const*,
CGPDFObject*, void*) | NSLog | NSLogv
| _CFLogvEx | __CFLogCString |
asl_send | _asl_send_level_message |
asl_set_query | strdup | malloc |
malloc_zone_malloc
2
FREE 0x4dbb160-0x4dbb171 [size=18]:
thread_a0375540 |start | main |
UIApplicationMain | GSEventRun |
GSEventRunModal | CFRunLoopRunInMode |
CFRunLoopRunSpecific | __CFRunLoopRun
| __CFRunLoopDoTimer |
__CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__
| __NSFireDelayedPerform |
-[todoListViewController drillDocumentMenu:] |
-[documentListViewController drillIntoDocumentWithToDoRecord:] |
-[documentViewController OpenTodoDocument:OfType:WithPath:] |
-[documentViewController OpenDocumentOfType:WithPath:] |
-[documentViewController managePDFDocumentWithPath:] |
-[PDFDocument loadPDFDocumentWithPath:andTitle:] |
-[PDFDocument getMetaData] | CGPDFDictionaryApplyFunction |
ListDictionaryObjects(char const*,
CGPDFObject*, void*) | NSLog | NSLogv
| _CFLogvEx | __CFLogCString |
asl_send | _asl_send_level_message |
asl_free | free
3
ALLOC 0x4dbb170-0x4dbb19f [size=48]:
thread_a0375540 |start | main |
UIApplicationMain | GSEventRun |
GSEventRunModal | CFRunLoopRunInMode |
CFRunLoopRunSpecific | __CFRunLoopRun
| __CFRunLoopDoTimer |
__CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__
| __NSFireDelayedPerform |
-[todoListViewController drillDocumentMenu:] |
-[documentListViewController drillIntoDocumentWithToDoRecord:] |
-[documentViewController OpenTodoDocument:OfType:WithPath:] |
-[documentViewController OpenDocumentOfType:WithPath:] |
-[documentViewController managePDFDocumentWithPath:] |
-[ScrollViewWithPagingViewController init] | -[UIView init] |
-[UIScrollView initWithFrame:] | -[UIView initWithFrame:] | UIViewCommonInitWithFrame | -[UIView
_createLayerWithFrame:] | +[NSObject(NSObject) alloc] | +[NSObject(NSObject) allocWithZone:] | class_createInstance |
_internal_class_createInstanceFromZone | calloc | malloc_zone_calloc
我不明白的是，如果它的历史是 ALLOC、FREE、ALLOC 那么为什么错误表明它已被释放（净 +1 分配）？
还是我对转储的理解是错误的？
编辑（新运行=不同的对象指针）：
用仪器检测僵尸：
为什么以及如何，保留计数从 1 跳到 -1？
查看 Zombie 的回溯，看起来保留计数被调用：Quartz through release_root_if_unused
编辑：已解决-我正在从 super 中删除一个视图，然后将其释放。只需释放它即可修复。