crash - 从 super 删除 View 时，iOS12.0.1上的应用程序崩溃

Question

Date/Time: 2018-10-30 00:57:35 +0000 OS Version: iPhone OS 12.0.1 (16A404) Report Version: 104

Exception Type:  SIGSEGV
Exception Codes: SEGV_ACCERR at 0x10
Crashed Thread:  0

Thread 0 Crashed: 0 libobjc.A.dylib
0x00000001aa9f0d70 objc_msgSend + 16 1 Foundation
0x00000001ac3c7958 NSLayoutConstraintIsPotentiallyDanglyInContainer + 112 2 UIKitCore 0x00000001d8b78464 -[UIView+ 13431908 (AdditionalLayoutSupport) _snipDangliesWithForce:repairIfPossibleForViewThatMoved:newSuperview:oldSuperview:] + 424 3 UIKitCore 0x00000001d8b781c8 _UIViewRemoveConstraintsMadeDanglyByChangingSuperview + 1088 4 UIKitCore 0x00000001d8c19f54 __45-[UIView+ 14094164 (Hierarchy) _postMovedFromSuperview:]_block_invoke + 68 5
UIKitCore 0x00000001d8c19e74 -[UIView+ 14093940 (Hierarchy) _postMovedFromSuperview:] + 756 6 UIKitCore
0x00000001d8c17f38 __UIViewWasRemovedFromSuperview + 172 7 UIKitCore 0x00000001d8c17a18 -[UIView+ 14084632 (Hierarchy) removeFromSuperview] + 464

我收到了这样的崩溃，只有ios12.0.1

Answer 1

我的声誉还不够高，无法发表评论，但是我经历了同样的崩溃，该崩溃仅在iOS 12上开始发生。我向Apple提交了错误报告，因此希望很快得到解决。

基于堆栈跟踪，它在尝试清理悬空约束时会崩溃，因此您可以尝试的一种可能的解决方法是在删除 View 之前先删除所有约束。

extension UIView {
    func removeAllConstraints() {
        let superViewConstraints = superview?.constraints.filter{ $0.firstItem === self || $0.secondItem === self } ?? []

        superview?.removeConstraints(superViewConstraints + constraints)
    }
}

...然后在删除 View 之前，只需调用:

view.removeAllConstraints() 

我不是100％肯定会成功，因为我自己无法重现崩溃，我只看到它在我使用的崩溃分析服务中弹出。