iOS 16中启动VNDocumentCameraViewController崩溃问题求助

问题说明 #

• 在iOS 16的iPad/iPhone设备上启动VNDocumentCameraViewController时触发致命错误，iOS 14、iOS 15等旧系统无此问题
• 已在info.plist中配置NSCameraUsageDescription权限字段
• 崩溃发生在调用self.present之后，无法正常显示相机界面

触发崩溃的代码 #

let myScanViewController = VNDocumentCameraViewController()
myScanViewController.delegate = self
self.present(myScanViewController, animated: false)

崩溃调试信息 #

Terminating app due to uncaught exception 'NSInvalidArgumentException', reason:
[__NSPlaceholderArray initWithObjects:count:]: attempt to insert nil object from objects[0]'

堆栈回溯日志 #

0   CoreFoundation                     0x18add6248 __exceptionPreprocess + 164
1   libobjc.A.dylib                        0x1841a3a68 objc_exception_throw + 60
2   CoreFoundation                     0x18af7a6d4 -[__NSCFString characterAtIndex:].cold.1 + 0
3   CoreFoundation                     0x18af77a74 -[__NSPlaceholderArray initWithCapacity:].cold.1 + 0
4   CoreFoundation                   0x18add1828 -[__NSPlaceholderArray initWithObjects:count:] + 252
5   CoreFoundation                   0x18add2b1c +[NSArray arrayWithObjects:count:] + 40
6   UIKitCore                              0x18d387f5c +[UIImageSymbolConfiguration configurationWithHierarchicalColor:] + 124
7   UIKitCore                              0x18d7ffd60 -[_UIImageCUIVectorGlyphContent _automaticSymbolConfiguration] + 104
8   UIKitCore                              0x18cff6434 -[UIImageView _symbolConfigurationForImage:] + 72
9   UIKitCore                              0x18cfc77cc -[UIImageView _resolvedImageFromImage:forTrait:] + 96
10  UIKitCore                              0x18cf941fc -[UIImageView _resolvedImageFromImage:] + 152
11  UIKitCore                              0x18cf92d5c -[UIButtonLegacyVisualProvider intrinsicSizeWithinSize:] + 132
12  UIKitCore                              0x18cf92cb4 -[UIButton _intrinsicSizeWithinSize:] + 52
13  UIKitCore                              0x18cfcd04c -[UIView(UIConstraintBasedLayout) intrinsicContentSize] + 120
14  UIKitCore                              0x18cfcd598 -[UIButton intrinsicContentSize] + 148
15  UIKitCore                              0x18cfccbe0 -[UIView _generateContentSizeConstraints] + 52
16  UIKitCore                              0x18cfb74a8 -[UIView _updateContentSizeConstraints] + 244
17  UIKitCore                              0x18d04b4a4 -[UIView(AdditionalLayoutSupport) _updateSystemConstraints] + 88
18  UIKitCore                              0x18d0c9700 -[UIButton updateConstraints] + 72
19  UIKitCore                              0x18d04b378 -[UIView(AdditionalLayoutSupport) _sendUpdateConstraintsIfNecessaryForSecondPass:] + 348
20  UIKitCore                              0x18d04b110 -[UIView(AdditionalLayoutSupport) _updateConstraintsIfNeededCollectingViews:forSecondPass:] + 764
21  UIKitCore                              0x18d04b02c -[UIView(AdditionalLayoutSupport) _updateConstraintsIfNeededCollectingViews:forSecondPass:] + 536
22  UIKitCore                              0x18d04b02c -[UIView(AdditionalLayoutSupport) _updateConstraintsIfNeededCollectingViews:forSecondPass:] + 536
23  UIKitCore                              0x18d04b02c -[UIView(AdditionalLayoutSupport) _updateConstraintsIfNeededCollectingViews:forSecondPass:] + 536
24  CoreAutoLayout                         0x1a72a7e90 -[NSISEngine withBehaviors:performModifications:] + 84
25  UIKitCore                              0x18d04ae08 __100-[UIView(AdditionalLayoutSupport) _updateConstraintsIfNeededWithViewForVariableChangeNotifications:]_block_invoke + 104
26  UIKitCore                              0x18cfed6e8 -[UIView(AdditionalLayoutSupport) _withUnsatisfiableConstraintsLoggingSuspendedIfEngineDelegateExists:] + 96
27  UIKitCore                              0x18cfed350 -[UIView(AdditionalLayoutSupport) _updateConstraintsIfNeededWithViewForVariableChangeNotifications:] + 172
28  UIKitCore                              0x18cfecf50 -[UIView(AdditionalLayoutSupport) _updateConstraintsAtEngineLevelIfNeededWithViewForVariableChangeNotifications:] + 388
29  UIKitCore                              0x18d02cdec -[UIView(Hierarchy) layoutBelowIfNeeded] + 1064
30  DocumentCamera                         0x1edf3c6c4 -[ICDocCamViewController initializeUserInterface] + 656
31  DocumentCamera                         0x1edf3baa4 -[ICDocCamViewController viewDidLoad] + 1044
32  UIKitCore                              0x18d2dd330 -[UIViewController _sendViewDidLoadWithAppearanceProxyObjectTaggingEnabled] + 84
33  UIKitCore                              0x18cf750a8 -[UIViewController loadViewIfRequired] + 712
34  UIKitCore                              0x18d23c1bc -[UINavigationController _updateScrollViewFromViewController:toViewController:] + 124
35  UIKitCore                              0x18d1025ec -[UINavigationController _startTransition:fromViewController:toViewController:] + 196
36  UIKitCore                              0x18d101aa4 -[UINavigationController _startDeferredTransitionIfNeeded:] + 608
37  UIKitCore                              0x18d1010f4 -[UINavigationController __viewWillLayoutSubviews] + 96
38  UIKitCore                              0x18d101058 -[UILayoutContainerView layoutSubviews] + 172
39  UIKitCore                              0x18cf5ecec -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 1980
40  QuartzCore                             0x18c43b4e8 CA::Layer::layout_if_needed(CA::Transaction*) + 500
41  QuartzCore                             0x18c44eb9c CA::Layer::layout_and_display_if_needed(CA::Transaction*) + 148
42  QuartzCore                             0x18c460098 CA::Context::commit_transaction(CA::Transaction*, double, double*) + 456
43  QuartzCore                             0x18c4973c4 CA::Transaction::commit() + 652
44  QuartzCore                             0x18c47e408 CA::Transaction::flush_as_runloop_observer(bool) + 88
45  CoreFoundation                         0x18ae5e070 __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 36
46  CoreFoundation                         0x18ade6690 __CFRunLoopDoObservers + 532
47  CoreFoundation                         0x18ae47f8c __CFRunLoopRun + 1048
48  CoreFoundation                         0x18ae4d1e4 CFRunLoopRunSpecific + 612
49  GraphicsServices                       0x1c3c6d368 GSEventRunModal + 164
50  UIKitCore                              0x18d2fcd88 -[UIApplication _run] + 888
51  UIKitCore                              0x18d2fc9ec UIApplicationMain + 340
52  digitrame                              0x1019c8d88 main + 64
53  dyld                                   0x1a9171948 start + 2504

排查与解决建议 #

从堆栈日志分析，崩溃根源是UIImageSymbolConfiguration初始化时传入了nil颜色值，导致数组插入nil对象。这通常和全局UIAppearance设置或自定义控件配置冲突有关，可按以下方向排查：

• 检查项目中针对UIButton、UIImageView或UIImageSymbolConfiguration的全局外观修改，尤其是涉及层级颜色（HierarchicalColor）的设置，确认是否存在传入nil值的情况
• 尝试在启动相机前临时重置全局UIAppearance配置，测试是否能规避崩溃：

  // 临时重置按钮相关外观
  UIButton.appearance().setTitleColor(nil, for: .normal)
  UIButton.appearance().setImage(nil, for: .normal)
  // 启动相机控制器
  let myScanViewController = VNDocumentCameraViewController()
  myScanViewController.delegate = self
  self.present(myScanViewController, animated: false)
  

• 确认项目中自定义的图片加载逻辑，特别是SF Symbols的处理，避免返回nil的Symbol配置
• 移除所有自定义外观设置，使用系统默认UI配置，验证是否为自定义代码导致的冲突

内容的提问来源于stack exchange，提问作者Pascal