在 iOS 13 上推送新视图后后退按钮崩溃

Posted 2023-02-24

【中文标题】在 iOS 13 上推送新视图后后退按钮崩溃

【英文标题】：Back button crashes after pushing a new view on iOS 13

【发布时间】：2019-08-28 11:16:22

【问题描述】：

我有一个在 ios 12 上完美运行的应用程序。我想在 iOS 13、XCode 11 上进行测试。我使用情节提要导航 segue 将一个视图控制器推送到另一个视图控制器。当我在第二页上按下后退按钮（默认后退按钮）时，应用程序崩溃并在下面产生错误。它发生在每个导航页面中，甚至是空视图。

2019-08-28 14:10:48.632540+0300 App Name[28453:400531] *** Assertion failure in -[UINavigationController _popNavigationBar:item:], /BuildRoot/Library/Caches/com.apple.xbs/Sources/UIKitCore_Sim/UIKit-3899.13.11/UINavigationController.m:8520
2019-08-28 14:10:48.642352+0300 App Name[28453:400531] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Override of -navigationBar:shouldPopItem: returned YES after manually popping a view controller (navigationController=<UINavigationController: 0x7fa22f0de000>)'
*** First throw call stack:
(
    0   CoreFoundation                      0x00007fff23afdbde __exceptionPreprocess + 350
    1   libobjc.A.dylib                     0x00007fff5015cb20 objc_exception_throw + 48
    2   CoreFoundation                      0x00007fff23afd958 +[NSException raise:format:arguments:] + 88
    3   Foundation                          0x00007fff255506f5 -[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:] + 191
    4   UIKitCore                           0x00007fff46812310 -[UINavigationController _popNavigationBar:item:] + 379
    5   UIKitCore                           0x00007fff46592209 -[UINavigationBar _sendNavigationPopForBackBarButtonItem:] + 277
    6   UIKitCore                           0x00007fff465bf771 -[_UINavigationBarContentView __backButtonAction:] + 58
    7   UIKitCore                           0x00007fff46f0abc1 -[UIApplication sendAction:to:from:forEvent:] + 83
    8   UIKitCore                           0x00007fff468fc3e5 -[UIControl sendAction:to:forEvent:] + 223
    9   UIKitCore                           0x00007fff468fc72f -[UIControl _sendActionsForEvents:withEvent:] + 398
    10  UIKitCore                           0x00007fff468fc892 -[UIControl _sendActionsForEvents:withEvent:] + 753
    11  UIKitCore                           0x00007fff468fb68e -[UIControl touchesEnded:withEvent:] + 481
    12  UIKitCore                           0x00007fff46f450c7 -[UIWindow _sendTouchesForEvent:] + 2604
    13  UIKitCore                           0x00007fff46f469ce -[UIWindow sendEvent:] + 4596
    14  UIKitCore                           0x00007fff46f2204f -[UIApplication sendEvent:] + 356
    15  UIKitCore                           0x00007fff46fa18c0 __dispatchPreprocessedEventFromEventQueue + 6847
    16  UIKitCore                           0x00007fff46fa4386 __handleEventQueueInternal + 5980
    17  CoreFoundation                      0x00007fff23a60ac1 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
    18  CoreFoundation                      0x00007fff23a609ec __CFRunLoopDoSource0 + 76
    19  CoreFoundation                      0x00007fff23a601c4 __CFRunLoopDoSources0 + 180
    20  CoreFoundation                      0x00007fff23a5aecf __CFRunLoopRun + 1263
    21  CoreFoundation                      0x00007fff23a5a6b6 CFRunLoopRunSpecific + 438
    22  GraphicsServices                    0x00007fff38016bb0 GSEventRunModal + 65
    23  UIKitCore                           0x00007fff46f0990f UIApplicationMain + 1621
    24  App Name                           0x000000010691b810 main + 112
    25  libdyld.dylib                       0x00007fff50fe1cf5 start + 1
    26  ???                                 0x0000000000000001 0x0 + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb) 

【问题讨论】：

您是否覆盖了 UINavigationBar 的 shouldPopItem 代表？

我刚刚添加了 UINavigationControllerDelegate、UINavigationBarDelegate。但是 shouldPopItem 没有被调用。

嘿，你找到解决办法了吗？

【参考方案1】：

创建UINavigationController 的自定义类，然后添加UINavigationBarDelegate 如下并将该类分配给您的UINavigationController

 class MyNavigationController: UINavigationController 

    override func viewDidLoad() 
        super.viewDidLoad()
        self.navigationBar.delegate = self
    


extension MyNavigationController : UINavigationBarDelegate 
    public func navigationBar(_ navigationBar: UINavigationBar, shouldPop item: UINavigationItem) -> Bool 
        return true
    

【讨论】：

现在它不会崩溃了。但不弹出视图控制器

【参考方案2】：

我不知道这对你来说是否仍然是个问题，但我有类似的事情（实际上我的问题是它在 ios13 上完美运行，但在 ios12 上后退按钮不起作用）。

错误告诉你不能手动弹出视图控制器然后返回true（即是的你应该弹出视图控制器）所以如果你手动弹出则需要返回false

override public func navigationBar(_ navigationBar: UINavigationBar, shouldPop item: UINavigationItem) -> Bool 
        popViewController(animated: true)
        return false