ios - 调试 'CALayer position contains NaN: [nan nan]'

Question

在将 Xcode 更新到 8.3 后，我在启动时开始收到此错误:由于未捕获的异常“CALayerInvalidGeometry”而终止应用程序，原因:“CALayer 位置包含 NaN:[nan nan]”

我的应用程序的主视图有几个容器 View ，其中一个包含一个 mapView。看来错误与 map 有关，但我无法从消息中完全弄清楚那可能是什么。任何想法将不胜感激!

*** Terminating app due to uncaught exception 'CALayerInvalidGeometry', reason: 'CALayer position contains NaN: [nan nan]'
*** First throw call stack:
(
0   CoreFoundation                      0x00000001029b1b0b __exceptionPreprocess + 171
1   libobjc.A.dylib                     0x0000000102416141 objc_exception_throw + 48
2   CoreFoundation                      0x0000000102a1a625 +[NSException raise:format:] + 197
3   QuartzCore                          0x00000001039d90be _ZN2CA5Layer12set_positionERKNS_4Vec2IdEEb + 152
4   QuartzCore                          0x00000001039d9231 -[CALayer setPosition:] + 43
5   MapKit                              0x000000010354a97b -[MKMapView _updateScrollContainerView:] + 1214
6   MapKit                              0x000000010354bbeb -[MKMapView _sizeDidChangeWithCenterCoordinate:] + 55
7   MapKit                              0x000000010354606e -[MKMapView setBounds:] + 271
8   UIKit                               0x0000000103c14b23 -[UIView(Geometry) _applyISEngineLayoutValuesToBoundsOnly:] + 598
9   UIKit                               0x0000000103c14e0e -[UIView(Geometry) _resizeWithOldSuperviewSize:] + 125
10  CoreFoundation                      0x0000000102942652 __53-[__NSArrayM enumerateObjectsWithOptions:usingBlock:]_block_invoke + 114
11  CoreFoundation                      0x000000010294256f -[__NSArrayM enumerateObjectsWithOptions:usingBlock:] + 335
12  UIKit                               0x0000000103c1387c -[UIView(Geometry) resizeSubviewsWithOldSize:] + 183
13  UIKit                               0x000000010452f1f9 -[UIView(AdditionalLayoutSupport) _is_layout] + 168
14  UIKit                               0x0000000103c1fd56 -[UIView(Hierarchy) _updateConstraintsAsNecessaryAndApplyLayoutFromEngine] + 994
15  UIKit                               0x0000000103c3120b -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 1268
16  QuartzCore                          0x00000001039e2904 -[CALayer layoutSublayers] + 146
17  QuartzCore                          0x00000001039d6526 _ZN2CA5Layer16layout_if_neededEPNS_11TransactionE + 370
18  QuartzCore                          0x00000001039d63a0 _ZN2CA5Layer28layout_and_display_if_neededEPNS_11TransactionE + 24
19  QuartzCore                          0x0000000103965e92 _ZN2CA7Context18commit_transactionEPNS_11TransactionE + 294
20  QuartzCore                          0x0000000103992130 _ZN2CA11Transaction6commitEv + 468
21  QuartzCore                          0x0000000103992b37 _ZN2CA11Transaction17observer_callbackEP19__CFRunLoopObservermPv + 115
22  CoreFoundation                      0x0000000102957717 __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 23
23  CoreFoundation                      0x0000000102957687 __CFRunLoopDoObservers + 391
24  CoreFoundation                      0x000000010293c038 CFRunLoopRunSpecific + 440
25  UIKit                               0x0000000103b6802f -[UIApplication _run] + 468
26  UIKit                               0x0000000103b6e0d4 UIApplicationMain + 159
27  Pulley                              0x0000000101bd95b7 main + 55
28  libdyld.dylib                       0x0000000109eaa65d start + 1
29  ???                                 0x0000000000000001 0x0 + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb) 

Answer 1

您似乎正在使用 CALayer 对象执行 setPosition: 并且 CALayer 对象为 nil。这就是您的应用崩溃的原因。

请通过if语句检查CALayer是否为nil。