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我创建了一个应用程序但是当我重命名我的一个ViewControllers时，应用程序现在崩溃了。
堆栈追踪：
*** Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[<netduma_v2.HostFilteringViewController 0x7fbb52d3dfa0> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key mapView.'
*** First throw call stack:
(
0 CoreFoundation 0x00000001097cde65 __exceptionPreprocess + 165
1 libobjc.A.dylib 0x0000000109246deb objc_exception_throw + 48
2 CoreFoundation 0x00000001097cdaa9 -[NSException raise] + 9
3 Foundation 0x0000000108e139bb -[NSObject(NSKeyValueCoding) setValue:forKey:] + 288
4 UIKit 0x0000000109fb4320 -[UIViewController setValue:forKey:] + 88
5 UIKit 0x000000010a1e2f41 -[UIRuntimeOutletConnection connect] + 109
6 CoreFoundation 0x000000010970e4a0 -[NSArray makeObjectsPerformSelector:] + 224
7 UIKit 0x000000010a1e1924 -[UINib instantiateWithOwner:options:] + 1864
8 UIKit 0x0000000109fbaeea -[UIViewController _loadViewFromNibNamed:bundle:] + 381
9 UIKit 0x0000000109fbb816 -[UIViewController loadView] + 178
10 UIKit 0x0000000109fbbb74 -[UIViewController loadViewIfRequired] + 138
11 UIKit 0x000000010a000651 -[UINavigationController _layoutViewController:] + 54
12 UIKit 0x000000010a000f26 -[UINavigationController _updateScrollViewFromViewController:toViewController:] + 462
13 UIKit 0x000000010a001098 -[UINavigationController _startTransition:fromViewController:toViewController:] + 126
14 UIKit 0x000000010a0022f1 -[UINavigationController _startDeferredTransitionIfNeeded:] + 890
15 UIKit 0x000000010a0033af -[UINavigationController __viewWillLayoutSubviews] + 57
16 UIKit 0x000000010a1a9ff7 -[UILayoutContainerView layoutSubviews] + 248
17 UIKit 0x0000000109edc4a3 -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 703
18 QuartzCore 0x000000010ff5059a -[CALayer layoutSublayers] + 146
19 QuartzCore 0x000000010ff44e70 _ZN2CA5Layer16layout_if_neededEPNS_11TransactionE + 366
20 QuartzCore 0x000000010ff44cee _ZN2CA5Layer28layout_and_display_if_neededEPNS_11TransactionE + 24
21 QuartzCore 0x000000010ff39475 _ZN2CA7Context18commit_transactionEPNS_11TransactionE + 277
22 QuartzCore 0x000000010ff66c0a _ZN2CA11Transaction6commitEv + 486
23 QuartzCore 0x000000010ff6737c _ZN2CA11Transaction17observer_callbackEP19__CFRunLoopObservermPv + 92
24 CoreFoundation 0x00000001096f9367 __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 23
25 CoreFoundation 0x00000001096f92d7 __CFRunLoopDoObservers + 391
26 CoreFoundation 0x00000001096eef2b __CFRunLoopRun + 1147
27 CoreFoundation 0x00000001096ee828 CFRunLoopRunSpecific + 488
28 GraphicsServices 0x000000010fe18ad2 GSEventRunModal + 161
29 UIKit 0x0000000109e25610 UIApplicationMain + 171
30 netduma-v2 0x00000001088d628d main + 109
31 libdyld.dylib 0x000000010c76a92d start + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
答案 0 :(得分：3)
您定义了一个实际上并不存在的连接插座mapView。要么是因为你没有设置VC的类，要么改变了类..
检查您的故事板是否有错误的插座/操作 - 标有（！）