当我使用CollectionView启动我的应用程序时：
2016-06-20 20:37:30.640 Projekt A[19055:699202] -[UIViewController collectionView:numberOfItemsInSection:]: unrecognized selector sent to instance 0x7fd1bbfa3ac0
2016-06-20 20:37:30.748 Projekt A[19055:699202] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[UIViewController collectionView:numberOfItemsInSection:]: unrecognized selector sent to instance 0x7fd1bbfa3ac0'
*** First throw call stack:
(
0 CoreFoundation 0x000000010f8d2d85 __exceptionPreprocess + 165
1 libobjc.A.dylib 0x0000000111854deb objc_exception_throw + 48
2 CoreFoundation 0x000000010f8dbd3d -[NSObject(NSObject) doesNotRecognizeSelector:] + 205
3 CoreFoundation 0x000000010f821cfa ___forwarding___ + 970
4 CoreFoundation 0x000000010f8218a8 _CF_forwarding_prep_0 + 120
5 UIKit 0x0000000110baa56c -[UICollectionViewData _updateItemCounts] + 492
6 UIKit 0x0000000110bad009 -[UICollectionViewData numberOfSections] + 22
7 UIKit 0x0000000110b8ef51 -[UICollectionViewFlowLayout _getSizingInfos] + 445
8 UIKit 0x0000000110b90c47 -[UICollectionViewFlowLayout _fetchItemsInfoForRect:] + 118
9 UIKit 0x0000000110b8a3fd -[UICollectionViewFlowLayout prepareLayout] + 273
10 UIKit 0x0000000110baac3d -[UICollectionViewData _prepareToLoadData] + 67
11 UIKit 0x0000000110bab411 -[UICollectionViewData validateLayoutInRect:] + 53
12 UIKit 0x0000000110b5853a -[UICollectionView layoutSubviews] + 199
13 UIKit 0x0000000110393980 -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 703
14 QuartzCore 0x0000000114a4ac00 -[CALayer layoutSublayers] + 146
15 QuartzCore 0x0000000114a3f08e _ZN2CA5Layer16layout_if_neededEPNS_11TransactionE + 366
16 QuartzCore 0x0000000114a3ef0c _ZN2CA5Layer28layout_and_display_if_neededEPNS_11TransactionE + 24
17 QuartzCore 0x0000000114a333c9 _ZN2CA7Context18commit_transactionEPNS_11TransactionE + 277
18 QuartzCore 0x0000000114a61086 _ZN2CA11Transaction6commitEv + 486
19 UIKit 0x000000011030519b _afterCACommitHandler + 174
20 CoreFoundation 0x000000010f7f7c37 __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 23
21 CoreFoundation 0x000000010f7f7ba7 __CFRunLoopDoObservers + 391
22 CoreFoundation 0x000000010f7ed7fb __CFRunLoopRun + 1147
23 CoreFoundation 0x000000010f7ed0f8 CFRunLoopRunSpecific + 488
24 GraphicsServices 0x000000011607cad2 GSEventRunModal + 161
25 UIKit 0x00000001102d8f09 UIApplicationMain + 171
26 Projekt A 0x000000010f6e4292 main + 114
27 libdyld.dylib 0x000000011238292d start + 1
28 ??? 0x0000000000000001 0x0 + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb)
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀ ⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀ 有人可以帮我吗？ ⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀ ⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀ ⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀ ⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀ ⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
答案 0 :(得分：1)
错误是集合视图的数据源设置为普通UIViewController，而不是您实现UICollectionViewDataSource的任何类。
检查数据源的分配方式以及对象的类别。