带有avplayeritem的doesNotRecognizeSelector崩溃

Question

我在一个看起来像是来自AVPlayerItem的回调中遇到了崩溃。我这样设置通知：

if (queuePlayer==nil) {
    queuePlayer = [[AVQueuePlayer alloc] initWithItems:playerItems];
}
else {
    for (AVPlayerItem* item in playerItems) {
        [queuePlayer insertItem:item afterItem:nil];
    }
}
[[NSNotificationCenter defaultCenter] addObserver:self
                                 selector:@selector(playerLastItemDidReachEnd:)
                                 name:AVPlayerItemDidPlayToEndTimeNotification
                                 object:[playerItems lastObject]];

[queuePlayer play];   
[playerItems release];

我以一种随机的方式得到这个崩溃；这意味着在大多数情况下，代码都是有效的。但是它会偶尔生成这种堆栈跟踪。

线程0名称:调度队列:com.apple.main-线程0已崩溃：

0   libsystem_kernel.dylib          0x30fbd350 __pthread_kill + 8
1   libsystem_c.dylib               0x3916a11e pthread_kill + 54
2   libsystem_c.dylib               0x391a696e abort + 90
3   libc++abi.dylib                 0x32515d4a abort_message + 70
4   libc++abi.dylib                 0x32512ff4 default_terminate() + 20
5   libobjc.A.dylib                 0x336c9a74 _objc_terminate() + 144
6   libc++abi.dylib                 0x32513078 safe_handler_caller(void (*)()) + 76
7   libc++abi.dylib                 0x32513110 std::terminate() + 16
8   libc++abi.dylib                 0x3251450e __cxa_throw + 118
9   libobjc.A.dylib                 0x336c99ba objc_exception_throw + 90
10  CoreFoundation                  0x353bce02 -[NSObject(NSObject) doesNotRecognizeSelector:] + 166
11  CoreFoundation                  0x353bb52c ___forwarding___ + 388
12  CoreFoundation                  0x35312f64 _CF_forwarding_prep_0 + 20
13  CoreFoundation                  0x3530a034 _CFXNotificationPost + 1424
14  AVFoundation                    0x317e6d60 __avplayeritem_fpItemNotificationCallback_block_invoke_0 + 3364
15  libdispatch.dylib               0x340aa11c _dispatch_call_block_and_release + 8
16  libdispatch.dylib               0x340a94b4 _dispatch_client_callout + 20
17  libdispatch.dylib               0x340ae1b8 _dispatch_main_queue_callback_4CF$VARIANT$mp + 220
18  CoreFoundation                  0x3538cf36 __CFRunLoopRun + 1286
19  CoreFoundation                  0x352ffeb8 CFRunLoopRunSpecific + 352
20  CoreFoundation                  0x352ffd44 CFRunLoopRunInMode + 100
21  GraphicsServices                0x3583c2e6 GSEventRunModal + 70
22  UIKit                           0x366de2fc UIApplicationMain + 1116
23  Training                        0x0004399a main (main.m:14)
24  Training                        0x0004395c start + 36

Answer 1

看起来您的对象实际上并没有playerLastItemDidReachEnd:选择器。