预览网络图片视频崩溃 —— 2.6.8 fix

[NorthDogLi]

5.7号：
刚下载的demo，点击 预览网络图片视频 左右滑动后崩溃：
*** Terminating app due to uncaught exception 'NSRangeException', reason: 'Cannot remove an observer <ZLPreviewNetVideo 0x7fb4c9da21f0> for the key path "playbackBufferEmpty" from <AVPlayerItem 0x6000000177f0> because it is not registered as an observer.'
*** First throw call stack:
(
0 CoreFoundation 0x000000011039012b __exceptionPreprocess + 171
1 libobjc.A.dylib 0x000000010f5dff41 objc_exception_throw + 48
2 CoreFoundation 0x0000000110405245 +[NSException raise:format:] + 197
3 Foundation 0x000000010f008f15 -[NSObject(NSKeyValueObserverRegistration) _removeObserver:forProperty:] + 497
4 Foundation 0x000000010f008ccb -[NSObject(NSKeyValueObserverRegistration) removeObserver:forKeyPath:] + 84
5 ZLPhotoBrowser 0x000000010da3d000 -[ZLPreviewNetVideo seekToZero] + 160
6 ZLPhotoBrowser 0x000000010da34082 -[ZLPreviewView handlerEndDisplaying] + 914
7 ZLPhotoBrowser 0x000000010da888e9 -[ZLShowBigImgViewController collectionView:didEndDisplayingCell:forItemAtIndexPath:] + 169
8 UIKit 0x00000001122e171f -[UICollectionView _notifyDidEndDisplayingCellIfNeeded:forIndexPath:] + 195
9 UIKit 0x00000001122e9dda __43-[UICollectionView _updateVisibleCellsNow:]_block_invoke_3 + 679
10 UIKit 0x00000001122e99a5 __43-[UICollectionView _updateVisibleCellsNow:]_block_invoke_2.982 + 337
11 CoreFoundation 0x0000000110314d72 -[__NSDictionaryM enumerateKeysAndObjectsWithOptions:usingBlock:] + 226
12 UIKit 0x00000001122e981c __43-[UICollectionView _updateVisibleCellsNow:]_block_invoke.981 + 195
13 UIKit 0x00000001122e6848 -[UICollectionView _updateVisibleCellsNow:] + 3652
14 UIKit 0x00000001122ecc21 -[UICollectionView layoutSubviews] + 364
15 UIKit 0x00000001118e0a6d -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 1439
16 QuartzCore 0x000000011164961c -[CALayer layoutSublayers] + 159
17 QuartzCore 0x000000011164d7ad _ZN2CA5Layer16layout_if_neededEPNS_11TransactionE + 401
18 QuartzCore 0x00000001115d486c _ZN2CA7Context18commit_transactionEPNS_11TransactionE + 364
19 QuartzCore 0x0000000111601946 _ZN2CA11Transaction6commitEv + 500
20 QuartzCore 0x000000011154e3cc _ZN2CA7Display11DisplayLink14dispatch_itemsEyyy + 960
21 QuartzCore 0x000000011168e894 ZL22display_timer_callbackP12__CFMachPortPvlS1 + 248
22 CoreFoundation 0x000000011031f899 __CFMachPortPerform + 169
23 CoreFoundation 0x000000011031f7d9 CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION + 41
24 CoreFoundation 0x000000011031f741 __CFRunLoopDoSource1 + 465
25 CoreFoundation 0x0000000110317524 __CFRunLoopRun + 2596
26 CoreFoundation 0x0000000110316889 CFRunLoopRunSpecific + 409
27 GraphicsServices 0x000000011c89b9c6 GSEventRunModal + 62
28 UIKit 0x000000011180f5d6 UIApplicationMain + 159
29 ZLPhotoBrowser 0x000000010da6f1df main + 111
30 libdyld.dylib 0x000000011488ad81 start + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException

[longitachi]

已查到原因，下个版本会更新解决