libc abi.dylib：以NSException CollectionViewtypes的未捕获exception终止
当我运行我的应用程序，我收到这个错误：
2014-08-11 10：52：10.546 ControlViewTest [918：60b] - [UIViewController collectionView：numberOfItemsInSection：]：无法识别的select器发送到实例0x8c862f0
2014-08-11 10：52：10.605 ControlViewTest [918：60b] *由于未捕获exception'NSInvalidArgumentException'，原因：' - [UIViewController collectionView：numberOfItemsInSection：]：无法识别的select器发送到实例0x8c862f0'
*首先掷出调用堆栈：
（
0 CoreFoundation 0x017ec1e4 exceptionPreprocess + 180
1 libobjc.A.dylib 0x0156b8e5 objc_exception_throw + 44
2 CoreFoundation 0x01889243 - [NSObject（NSObject）doesNotRecognizeSelector：] + 275
3 CoreFoundation 0x017dc50b ___forwarding_ + 1019
4 CoreFoundation 0x017dc0ee _CF_forwarding_prep_0 + 14
5 UIKit 0x008b0c34 - [UICollectionViewData _updateItemCounts] + 331
6 UIKit 0x008b0ce1 - [UICollectionViewData _validateItemCounts] + 45
7 UIKit 0x008b2c64 - [UICollectionViewData numberOfSections] + 35
8 UIKit 0x0087d6ed - [UICollectionView numberOfSections] + 62
9 UIKit 0x0089d614 - [UICollectionViewFlowLayout（Internal）_getSizingInfos] + 205
10 UIKit 0x0089e48f - [UICollectionViewFlowLayout（Internal）_fetchItemsInfo] + 521
11 UIKit 0x00899fe2 - [UICollectionViewFlowLayout prepareLayout] + 157
12 UIKit 0x008b0d9d - [UICollectionViewData _prepareToLoadData] + 76
13 UIKit 0x008b15c5 - [UICollectionViewData validateLayoutInRect：] + 56
14 UIKit 0x00877603 - [UICollectionView layoutSubviews] + 173
15 UIKit 0x0029a964 - [UIView（CALayerDelegate）layoutSublayersOfLayer：] + 355
16 libobjc.A.dylib 0x0157d82b - [NSObject performSelector：withObject：] + 70
17 QuartzCore 0x03c5745a - [CALayer layoutSublayers] + 148
18 QuartzCore 0x03c4b244 _ZN2CA5Layer16layout_if_neededEPNS_11TransactionE + 380
19 QuartzCore 0x03c573a5 - [CALayer layoutIfNeeded] + 160
20 UIKit 0x0035cae3 - [UIViewController窗口：setupWithInterfaceOrientation：] + 304
21 UIKit 0x00272aa7 - [UIWindow _setRotatableClient：toOrientation：updateStatusBar：duration：force：isRotating：] + 5212
22 UIKit 0x00271646 - [UIWindow _setRotatableClient：toOrientation：updateStatusBar：duration：force：] + 82
23 UIKit 0x00271518 - [UIWindow _setRotatableViewOrientation：updateStatusBar：duration：force：] + 117
24 UIKit 0x002715a0 - [UIWindow _setRotatableViewOrientation：duration：force：] + 67
25 UIKit 0x0027063a 57- [UIWindow _updateToInterfaceOrientation：duration：force：] _ block_invoke + 120
26 UIKit 0x0027059c - [UIWindow _updateToInterfaceOrientation：duration：force：] + 400
27 UIKit 0x002712f3 - [UIWindow setAutorotates：forceUpdateInterfaceOrientation：] + 870
28 UIKit 0x002748e6 - [UIWindow setDelegate：] + 449
29 UIKit 0x0034eb77 - [UIViewController _tryBecomeRootViewControllerInWindow：] + 180
30 UIKit 0x0026a474 - [UIWindow addRootViewControllerViewIfPossible] + 591
31 UIKit 0x0026a5ef - [UIWindow _setHidden：forced：] + 312
32 UIKit 0x0026a86b - [UIWindow _orderFrontWithoutMakingKey] + 49
33 UIKit 0x002753c8 - [UIWindow makeKeyAndVisible] + 65
34 UIKit 0x00225bc0 - [UIApplication _callInitializationDelegatesForURL：payload：suspended：] + 2097
35 UIKit 0x0022a667 - [UIApplication _runWithURL：payload：launchOrientation：statusBarStyle：statusBarHidden：] + 824
36 UIKit 0x0023ef92 - [UIApplication handleEvent：withNewEvent：] + 3517
UIKit 0x0023f555 - [UIApplication sendEvent：] + 85
38 UIKit 0x0022c250 _UIApplicationHandleEvent + 683
39 GraphicsServices 0x037e1f02 _PurpleEventCallback + 776
40 GraphicsServices 0x037e1a0d PurpleEventCallback + 46
41 CoreFoundation 0x01767ca5 __CFRUNLOOP_IS_CALLING_OUT_AT_A_SOURCE1_PERFORM_FUNCTION + 53
42 CoreFoundation 0x017679db __CFRunLoopDoSource1 + 523
43 CoreFoundation 0x0179268c __CFRunLoopRun + 2156
44 CoreFoundation 0x017919d3 CFRunLoopRunSpecific + 467
45 CoreFoundation 0x017917eb CFRunLoopRunInMode + 123
46 UIKit 0x00229d9c - [UIApplication _run] + 840
47 UIKit 0x0022bf9b UIApplicationMain + 1225
48 ControlViewTest 0x0000264d main + 141
49 libdyld.dylib 0x01e33701 start + 1
）
libc ++ abi.dylib：以NSExceptiontypes的未捕获exception终止
（LLDB）
有人可以帮助我
你的UICollectionView有一个数据源集合，它没有实现所需的方法collectionView:numberOfItemsInSection: UICollectionView 您需要为您的UICollectionView分配一个有效的数据源：您已经编写并实现了collectionView:numberOfItemsInSection:一个类。