ios - UINavigationController 推送因无法识别的选择器 barStyle 而崩溃

Question

很确定这是一个内存相关的问题，但它总是发生在同一个地方，当我将一个新 Controller 推到导航 Controller 堆栈上时

CurrentActivityViewController *controller = [[CurrentActivityViewController alloc] init];
controller.delegate = self;
[controller setModalTransitionStyle:UIModalTransitionStyleFlipHorizontal];
[self.navigationController presentViewController:controller animated:NO completion:nil];

崩溃总是有一个随机的接收对象，但总是在相同的堆栈调用之前，这是另一个有趣的花絮，这似乎只发生在运行 7.0 的 4 和 4s 设备上，似乎无法在运行 7.0 的模拟器上重现3.5 英寸设备，再次回到内存问题，所以不会有太大帮助。

Thread : Crashed: com.apple.main-thread
0  libobjc.A.dylib                0x39b42b26 objc_msgSend + 5
1  UIKit                          0x32039677 -[_UINavigationPaletteBackground _syncWithBarStyles] + 42
2  UIKit                          0x3203924b -[_UINavigationPaletteBackground updateBackgroundView] + 94
3  UIKit                          0x324e4bd3 +[_UIBackdropView setAllBackdropViewsToGraphicsQuality:] + 458
4  UIKit                          0x31f297b5 __85-[UIView(Hierarchy) _makeSubtreePerformSelector:withObject:withObject:copySublayers:]_block_invoke + 76
5  UIKit                          0x31f296e5 -[UIView(Hierarchy) _makeSubtreePerformSelector:withObject:withObject:copySublayers:] + 376
6  UIKit                          0x31f297d5 __85-[UIView(Hierarchy) _makeSubtreePerformSelector:withObject:withObject:copySublayers:]_block_invoke + 108
7  UIKit                          0x31f296e5 -[UIView(Hierarchy) _makeSubtreePerformSelector:withObject:withObject:copySublayers:] + 376
8  UIKit                          0x31f365c3 -[UIView(Internal) _addSubview:positioned:relativeTo:] + 418
9  UIKit                          0x31f36417 -[UIView(Hierarchy) addSubview:]
10 UIKit                          0x32017d8f -[UITransitionView transition:fromView:toView:removeFromView:] + 978
11 UIKit                          0x320173b3 __101-[UIWindowController transition:fromViewController:toViewController:target:didEndSelector:animation:]_block_invoke_2
12 UIKit                          0x320151b1 -[UIWindowController transition:fromViewController:toViewController:target:didEndSelector:animation:]
13 UIKit                          0x32012e25 -[UIViewController presentViewController:withTransition:completion:] + 4668
14 roadid                         0x001195b7 __67-[NewActivitySetupViewController activityViewControllerStartTimer:]_block_invoke (NewActivitySetupViewController.m:1372)

事情是它与最随机的对象一起崩溃，但总是与 barStyle 选择器一起崩溃，在我的应用程序委托(delegate)中，我使用 UIAppearance 代理在 UINavigationController 上设置一些样式，这是我唯一的地方甚至搞乱了 UINavigationController 样式，但从来没有特别 barStyle

if([self iOSIdentifier] == iOSVersion7)
{
    [[UINavigationBar appearance] setBackgroundImage:[UIImage imageNamed:@"titlebar_iOS7.png"] forBarMetrics:UIBarMetricsDefault];
} else {
    [[UINavigationBar appearance] setBackgroundImage:[UIImage imageNamed:@"title_bar.png"] forBarMetrics:UIBarMetricsDefault];
}
[[UINavigationBar appearance] setTitleTextAttributes:@{UITextAttributeTextColor: [UIColor whiteColor],
                                                       UITextAttributeTextShadowColor: [UIColor colorWithRed:0.0 green:0.0 blue:0.0 alpha:0.8f],
                                                       UITextAttributeTextShadowOffset: [NSValue valueWithUIOffset:UIOffsetMake(0, -1)]}];
[[UINavigationBar appearanceWhenContainedIn:[ABPeoplePickerNavigationController class],[ABNewPersonViewController class], nil] setBackgroundImage:nil forBarMetrics:UIBarMetricsDefault];

[[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleLightContent];

最后，这似乎是苹果内部使用 uinavigation Controller 的崩溃，但如果不重现这个，我就无法提交错误报告，关于在哪里寻找问题有什么想法吗？

Answer 1

如果这是模态视图，则需要从当前 View Controller 本身呈现它，而不是从它的导航 Controller

这一行...

[self.navigationController presentViewController:controller animated:NO completion:nil];

应该是……

[self presentViewController:controller animated:NO completion:nil];

看看 Apple Docs了解更多信息