iphone - [AVPlaybackItem fpItem] : message sent to deallocated instance

Question

我用 MPMoviePlayerController 播放电影。稍后，应用程序被“重新启动”(意味着伪重置，所有 viewController 被移除，用户返回主屏幕)，再次播放同一部电影。

这会导致 iPad 上的 iOS 3.2.2 崩溃:

[AVPlaybackItem fpItem]: message sent to deallocated instance

我不知道那是从哪里来的。似乎是私有(private)的东西。有没有人经历过并可能解决了同样的问题？

该特定地址的堆栈跟踪:

(gdb) info malloc 0x11471400
Alloc: Block address: 0x11471400 length: 76
Stack - pthread: 0xa0630500 number of frames: 34
    0: 0x9534e0c3 in malloc_zone_calloc
    1: 0x9534e01a in calloc
    2: 0x343edc9 in _internal_class_createInstanceFromZone
    3: 0x344b5c9 in _class_createInstanceFromZone
    4: 0x344b5ef in class_createInstance
    5: 0x3326b57 in +[NSObject allocWithZone:]
    6: 0x332583a in +[NSObject alloc]
    7: 0x536ab67 in -[AVPlaybackQueue queueItemWasAddedNotification:]
    8: 0x27f586 in _nsnote_callback
    9: 0x328d165 in _CFXNotificationPostNotification
   10: 0x2762ca in -[NSNotificationCenter postNotificationName:object:userInfo:]
   11: 0x5354982 in -[AVQueue itemWasAdded:atIndex:]
   12: 0x5354801 in -[AVQueue insertItem:atIndex:error:]
   13: 0x53549d8 in -[AVQueue appendItem:error:]
   14: 0x535c3be in -[AVController addNextFeederItemToQueue]
   15: 0x535b06f in -[AVController checkQueueSpace]
   16: 0x5359f46 in -[AVController setQueue:]
   17: 0x535ac62 in -[AVController setQueueFeeder:withIndex:]
   18: 0x30eee20 in -[MPAVController reloadFeederWithStartIndex:]
   19: 0x30deed7 in -[MPMoviePlayerControllerNew _prepareToPlayWithStartIndex:]
   20: 0x30dc686 in -[MPMoviePlayerControllerNew prepareToPlay]
   21: 0x27f586 in _nsnote_callback
   22: 0x328d165 in _CFXNotificationPostNotification
   23: 0x2762ca in -[NSNotificationCenter postNotificationName:object:userInfo:]
   24: 0x281238 in -[NSNotificationCenter postNotificationName:object:]
   25: 0x31596d1 in -[MPMovie _determineMediaType]
   26: 0x291b87 in __NSFireDelayedPerform
   27: 0x32747dc in CFRunLoopRunSpecific
   28: 0x32738a8 in CFRunLoopRunInMode
   29: 0x3aaf89d in GSEventRunModal
   30: 0x3aaf962 in GSEventRun
   31: 0x52b372 in UIApplicationMain
   32: 0x27be in main at /blablabla 
   33: 0x2735 in start

Answer 1

听起来你在打电话 release比你打电话的更多retain .

错误消息末尾是否不包含十六进制地址？如果是这样，请按照以下步骤查找有问题的对象:

导航到 Project->Edit Active Executable(或按 Command-Option-X)。选择参数选项卡。设置环境变量如下图:

运行程序并重复重现错误所需的步骤。

复制错误末尾的十六进制地址。然后，在调试器控制台中输入以下命令:(gdb) info malloc-history <paste-address-here> .

检查输出以寻找有问题的对象。

附言完成后不要忘记禁用环境变量。