在Xcode 5.0.2中,我创建了一个简单的iPhone应用程序(源代码可在GitHub上获得),该应用程序带有导航控制器,首先显示一个包含Facebook oAuth对话框的Web视图,并且 - 一旦用户已经被认证并且其详细信息已被获取 - 尝试推送DetailViewController:
Facebook用户数据已成功获取并几乎立即打印出来:
这种行为的原因可能是什么呢?
更新:
我已经按照Savana的建议清理了IBOutlets,但应用程序仍然崩溃:
[self performSegueWithIdentifier: @"segue" sender: self];
NSLog(@"id: %@", dict[@"id"]);
NSLog(@"first_name: %@", dict[@"first_name"]);
NSLog(@"last_name: %@", dict[@"last_name"]);
NSLog(@"gender: %@", dict[@"gender"]);
NSLog(@"city: %@", dict[@"location"][@"name"]);
Facebook用户数据已成功获取并几乎立即打印出来:
id: 597287941
first_name: Alexander
last_name: Farber
gender: male
city: Bochum, Germany
但是有时在进行转换之前会等待约一分钟,或者有时甚至会因为以下错误而崩溃:
2014-01-09 22:11:29.017 oauthFacebook[4012:1403] *** Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[<DetailViewController 0x8a89cd0> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key id.'
*** First throw call stack:
(
0 CoreFoundation 0x0173b5e4 __exceptionPreprocess + 180
1 libobjc.A.dylib 0x014be8b6 objc_exception_throw + 44
2 CoreFoundation 0x017cb6a1 -[NSException raise] + 17
3 Foundation 0x0117f9ee -[NSObject(NSKeyValueCoding) setValue:forUndefinedKey:] + 282
4 Foundation 0x010ebcfb _NSSetUsingKeyValueSetter + 88
5 Foundation 0x010eb253 -[NSObject(NSKeyValueCoding) setValue:forKey:] + 267
6 Foundation 0x0114d70a -[NSObject(NSKeyValueCoding) setValue:forKeyPath:] + 412
7 UIKit 0x004cea15 -[UIRuntimeOutletConnection connect] + 106
8 libobjc.A.dylib 0x014d07d2 -[NSObject performSelector:] + 62
9 CoreFoundation 0x01736b6a -[NSArray makeObjectsPerformSelector:] + 314
10 UIKit 0x004cd56e -[UINib instantiateWithOwner:options:] + 1417
11 UIKit 0x0033f605 -[UIViewController _loadViewFromNibNamed:bundle:] + 280
12 UIKit 0x0033fdad -[UIViewController loadView] + 302
13 UIKit 0x003400ae -[UIViewController loadViewIfRequired] + 78
14 UIKit 0x003405b4 -[UIViewController view] + 35
15 UIKit 0x0035a3e2 -[UINavigationController _startCustomTransition:] + 778
16 UIKit 0x003670c7 -[UINavigationController _startDeferredTransitionIfNeeded:] + 688
17 UIKit 0x00367cb9 -[UINavigationController __viewWillLayoutSubviews] + 57
18 UIKit 0x004a1181 -[UILayoutContainerView layoutSubviews] + 213
19 UIKit 0x00297267 -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 355
20 libobjc.A.dylib 0x014d081f -[NSObject performSelector:withObject:] + 70
21 QuartzCore 0x03b492ea -[CALayer layoutSublayers] + 148
22 QuartzCore 0x03b3d0d4 _ZN2CA5Layer16layout_if_neededEPNS_11TransactionE + 380
23 QuartzCore 0x03b3cf40 _ZN2CA5Layer28layout_and_display_if_neededEPNS_11TransactionE + 26
24 QuartzCore 0x03aa4ae6 _ZN2CA7Context18commit_transactionEPNS_11TransactionE + 294
25 QuartzCore 0x03aa5e71 _ZN2CA11Transaction6commitEv + 393
26 QuartzCore 0x03aa60c2 _ZN2CA11Transaction14release_threadEPv + 226
27 libsystem_pthread.dylib 0x01e7681c _pthread_tsd_cleanup + 93
28 libsystem_pthread.dylib 0x01e7327e _pthread_exit + 108
29 libsystem_pthread.dylib 0x01e73dd8 pthread_workqueue_setdispatchoffset_np + 0
30 libsystem_pthread.dylib 0x01e77cce start_wqthread + 30
)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb)
这种行为的原因可能是什么呢?
更新:
我已经按照Savana的建议清理了IBOutlets,但应用程序仍然崩溃:
2014-01-10 10:26:59.379 oauthFacebook[4342:4113] bool _WebTryThreadLock(bool), 0x8be2960: Tried to obtain the web lock from a thread other than the main thread or the web thread. This may be a result of calling to UIKit from a secondary thread. Crashing now...
1 0x51481ae WebThreadLock
2 0x452a57 -[UIWebDocumentView _responderForBecomeFirstResponder]
3 0x27da9e -[UIView setUserInteractionEnabled:]
4 0x934d72 -[_UIViewControllerTransitionContext _disableInteractionForViews:]
5 0x368573 -[UINavigationController pushViewController:transition:forceImmediate:]
6 0x3680b5 -[UINavigationController pushViewController:animated:]
7 0x770c65 -[UIStoryboardPushSegue perform]
8 0x76107e -[UIStoryboardSegueTemplate _perform:]
9 0x342280 -[UIViewController performSegueWithIdentifier:sender:]
10 0x29f0 __32-[ViewController fetchFacebook:]_block_invoke
11 0x11da695 __67+[NSURLConnection sendAsynchronousRequest:queue:completionHandler:]_block_invoke_2
12 0x113a945 -[NSBlockOperation main]
13 0x1193829 -[__NSOperationInternal _start:]
14 0x1110558 -[NSOperation start]
15 0x1195af4 __NSOQSchedule_f
16 0x1ae74b0 _dispatch_client_callout
17 0x1ad4018 _dispatch_async_redirect_invoke
18 0x1ae74b0 _dispatch_client_callout
19 0x1ad5eeb _dispatch_root_queue_drain
20 0x1ad6137 _dispatch_worker_thread2
21 0x1e73dab _pthread_wqthread
22 0x1e77cce start_wqthread
(lldb)
当我在performSegueWithIdentifier
调用之前添加assert([NSThread isMainThread]);
时,我可以看到这不是主线程...
调用performSegueWithIdentifier
是否需要在主线程上执行?