iOS7上的iOS宽高比约束中断,适用于iOS8

Question

在我的应用程序中,我设置了一个UIView的约束,其高度使用宽高比约束从其宽度计算.它在iOS8上完美适用于每个设备屏幕尺寸(3.5,4,4.7,5.5),但它会导致应用程序在每个iOS7设备上崩溃.

我认为它是宽高比约束,因为如果我用固定高度约束替换它,它不会再崩溃(显然它在某些设备上看起来很糟糕).

堆栈跟踪非常长,所以我只复制它的一部分.

预先感谢您的帮助!

Objective: {objective 0x7f9d90da33c0: <750:4692, 251:2936, 250:367> + <251:-1>*0x7f9d90c06220.marker{id: 592} + <251:-1>*0x7f9d90c24420.marker{id: 599} + <251:-1>*0x7f9d90c25650.marker{id: 594} + <251:-1>*0x7f9d90c27ad0.marker{id: 597} + <750:-1>*0x7f9d90c3b270.marker{id: 483} + <250:-3.9875>*0x7f9d90c43e40.marker{id: 618} + <250:-3.9875>*0x7f9d90c43e90.marker{id: 620} + <750:-4>*0x7f9d90c442e0.marker{id: 479} + <251:1>*0x7f9d90c464b0.marker{id: 485} + <251:-1>*0x7f9d90c46bf0.marker{id: 504} + <251:-1>*0x7f9d90c46c90.marker{id: 508} + <251:-1>*0x7f9d90c46ce0.marker{id: 510} + <251:-1>*0x7f9d90c46d80.marker{id: 514} + <251:-2>*0x7f9d90c4aa60.marker{id: 623} + <251:-2>*0x7f9d90c4aab0.marker{id: 625} + <251:-2, 250:-3.9875>*0x7f9d90c4ab50.marker{id: 631} + <251:-2, 250:-3.9875>*0x7f9d90c4abf0.marker{id: 634} + <251:4, 250:3.9875>*0x7f9d90c4ac40.marker{id: 637} + <251:4, 250:3.9875>*0x7f9d90c4ac90.marker{id: 642} + <750:1, 251:1>*0x7f9d90c4c530.negError{id: 645} + <750:1, 251:1>*0x7f9d90c4cb20.posErrorMarker{id: 646} + <750:1, 251:1>*0x7f9d90c530f0.negError{id: 649} + <750:1, 251:1>*0x7f9d90c53150.negError{id: 651} + <750:1, 250:1>*0x7f9d90c53820.posErrorMarker{id: 652} + <750:1, 250:1>*0x7f9d90c538a0.posErrorMarker{id: 654} + <750:1, 250:1>*0x7f9d90c53fd0.posErrorMarker{id: 656} + <750:1, 250:1>*0x7f9d90c54070.posErrorMarker{id: 658} + <750:1, 251:1>*0x7f9d90c54650.negError{id: 661} + <750:1>*0x7f9d90c546b0.negError{id: 663} + <251:1>*0x7f9d90c546b0.posErrorMarker{id: 662} + <750:1>*0x7f9d90c55230.negError{id: 665} + <251:1>*0x7f9d90c55230.posErrorMarker{id: 664} + <750:1, 251:1>*0x7f9d90c552b0.negError{id: 667} + <750:1, 251:1>*0x7f9d90d34300.posErrorMarker{id: 916} + <750:1>*0x7f9d90de48a0.marker{id: 738} + <250:-1>*0x7f9d90de48f0.marker{id: 740} + <250:-1>*0x7f9d90de4940.marker{id: 744} + <750:1>*0x7f9d90de4990.marker{id: 745} + <750:1>*0x7f9d90de4c70.marker{id: 718} + <750:1>*0x7f9d90de4cc0.marker{id: 720} + <250:-1

...

 Integralization Adjustments:
0x7f9d93042a90.marker{id: 532} [<NSLayoutConstraint:0x7f9d93042a90 UIView:0x7f9d9303d590.width == 1.50943*UIView:0x7f9d9303d590.height>] -> 0.132066
0x7f9d93042c70.marker{id: 546} [<NSLayoutConstraint:0x7f9d93042c70 UIButton:0x7f9d90de27a0.height == UIButton:0x7f9d93018ab0.height>] -> 1.000000
0x7f9d93042d60.marker{id: 552} [<NSLayoutConstraint:0x7f9d93042d60 UIButton:0x7f9d9303dbf0.width == UIButton:0x7f9d93018ab0.width>] -> -1.000000
0x7f9d93042db0.marker{id: 554} [<NSLayoutConstraint:0x7f9d93042db0 UIButton:0x7f9d9303dbf0.height == UIButton:0x7f9d93033b40.height>] -> 1.000000
0x7f9d93042ea0.marker{id: 562} [<NSLayoutConstraint:0x7f9d93042ea0 UIButton:0x7f9d93033b40.width == UIButton:0x7f9d9303c500.width>] -> -1.000000
0x7f9d930431c0.marker{id: 581} [<NSLayoutConstraint:0x7f9d930431c0 UIButton:0x7f9d9303c500.height == UIButton:0x7f9d93045880.height>] -> 1.000000

  Statistics:
    195 rows. Variable counts:
          1 ->  59
          2 ->  28
          3 ->   3
          4 ->   7
          5 ->   4
          6 ->   3
          7 ->   3
          8 ->   4
          9 ->   8
         10 ->  10
         11 ->  11
         12 ->  10
         13 ->   7
         14 ->   2
         15 ->   3
         16 ->  10
         17 ->  17
         18 ->   6
}: internal error.  Cannot find an outgoing row head for incoming head UIView:0x7f9d930332a0.Height{id: 981}, which should never happen.'
*** First throw call stack:
(
    0   CoreFoundation                      0x000000011284d495 __exceptionPreprocess + 165
    1   libobjc.A.dylib                     0x000000011220699e objc_exception_throw + 43
    2   CoreFoundation                      0x000000011284d2ad +[NSException raise:format:] + 205
    3   Foundation                          0x0000000110dfb054 -[NSISEngine minimizeConstantInObjectiveRowWithHead:] + 178
    4   Foundation                          0x0000000110dfaf22 -[NSISEngine optimize] + 147
    5   Foundation                          0x0000000110f432e3 -[NSISEngine withBehaviors:performModifications:] + 192
    6   UIKit                               0x000000011126f889 -[UIView(Hierarchy) _postMovedFromSuperview:] + 321
    7   UIKit                               0x000000011126df42 __UIViewWasRemovedFromSuperview + 206
    8   UIKit                               0x000000011126db9e -[UIView(Hierarchy) removeFromSuperview] + 218
    9   UIKit                               0x0000000111330069 -[UINavigationController navigationTransitionView:didEndTransition:fromView:toView:] + 320
    10  UIKit                               0x0000000111328fdd __49-[UINavigationController _startCustomTransition:]_block_invoke + 138
    11  UIKit                               0x000000011187ec2a -[_UIViewControllerTransitionContext completeTransition:] + 78
    12  UIKit                               0x0000000111211da4 __53-[_UINavigationParallaxTransition animateTransition:]_block_invoke103 + 605
    13  UIKit                               0x00000001112746e8 -[UIViewAnimationBlockDelegate _didEndBlockAnimation:finished:context:] + 299
    14  UIKit                               0x000000011126068e -[UIViewAnimationState sendDelegateAnimationDidStop:finished:] + 235
    15  UIKit                               0x0000000111260941 -[UIViewAnimationState animationDidStop:finished:] + 78
    16  UIKit                               0x000000011ef6d4b7 -[UIViewAnimationStateAccessibility(SafeCategory) animationDidStop:finished:] + 48
    17  QuartzCore                          0x0000000110ac9134 _ZN2CA5Layer23run_animation_callbacksEPv + 310
    18  libdispatch.dylib                   0x000000011327772d _dispatch_client_callout + 8
    19  libdispatch.dylib                   0x00000001132673fc _dispatch_main_queue_callback_4CF + 354
    20  CoreFoundation                      0x00000001128ab289 __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 9
    21  CoreFoundation                      0x00000001127f8854 __CFRunLoopRun + 1764
    22  CoreFoundation                      0x00000001127f7d83 CFRunLoopRunSpecific + 467
    23  GraphicsServices                    0x0000000114223f04 GSEventRunModal + 161
    24  UIKit                               0x000000011121be33 UIApplicationMain + 1010
    25  Playchat                            0x000000010fa89513 main + 115
    26  libdyld.dylib                       0x00000001134fa5c9 start + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException

Answer 1

这是一个烦人的错误,也花了我很多时间.我有完全相同的问题,该应用程序在iOS 8中工作正常但在iOS 7.1中崩溃.问题是滚动视图上的宽高比约束.在尝试了很多不同的东西之后,这终于解决了这个问题:

崩溃似乎是浮点计算在某些时候失败的结果.就我而言,我已经定义了16:9或更确切地说是9:16的宽高比,相当于0.5625. 将乘数从0.5625更改为0.5624解决了问题,此后不再出现崩溃.

Answer 2

我通过以下方式解决了它：

假设我的面板在 iPhone 4、4s、5、5s 上看起来相同，因为它们具有相同的宽度，因此它们的长宽比将导致相同的高度。我向添加纵横比约束的同一视图添加了高度约束。因此，无论 iOS 版本如何，在这些设备上，视图在高度限制下看起来都是正确的。

iPhone6和6+只能在iOS8或更高版本上运行，其中宽高比约束不会失效，如果iOS版本是8或更高版本，我只需删除高度约束，否则我删除宽高比约束。

它远非优雅，但以简单的方式解决了问题。