Question

我正在尝试展示我的＆＃34; ProtectedViewController＆＃34;。

let storyboard = UIStoryboard(name: "Main", bundle: nil)
let controller: UIViewController = storyboard.instantiateViewController(withIdentifier: "Protected") as! ProtectedPageViewController
self.present(controller, animated: true, completion: nil)

当我尝试显示时，错误会在步骤

上弹出

self.present(controller, animated: true, completion: nil)

如下面的屏幕截图：

以下代码也不起作用：

let pvc = ProtectedPageViewController()
self.present(pvc, animated: true, completion: nil)

同样的错误。已经尝试了一切。

堆栈跟踪错误：

 *** First throw call stack:
(
    0   CoreFoundation                      0x0000000108a2c34b __exceptionPreprocess + 171
    1   libobjc.A.dylib                     0x000000010807021e objc_exception_throw + 48
    2   CoreFoundation                      0x0000000108a30442 +[NSException raise:format:arguments:] + 98
    3   Foundation                          0x0000000107c06edd -[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:] + 195
    4   UIKit                               0x0000000109be1942 -[UIKeyboardTaskQueue waitUntilAllTasksAreFinished] + 165
    5   UIKit                               0x000000010934ec14 -[UIKeyboardImpl setDelegate:force:] + 1404
    6   UIKit                               0x0000000109776152 -[UIPeripheralHost(UIKitInternal) _reloadInputViewsForResponder:] + 981
    7   UIKit                               0x000000010977f95c -[UIPeripheralHost(UIKitInternal) _preserveInputViewsWithId:animated:reset:] + 498
    8   UIKit                               0x00000001092409b7 -[UIViewController _presentViewController:modalSourceViewController:presentationController:animationController:interactionController:completion:] + 1178
    9   UIKit                               0x0000000109242702 -[UIViewController _presentViewController:withAnimationController:completion:] + 4971
    10  UIKit                               0x00000001092456df -[UIViewController _performCoordinatedPresentOrDismiss:animated:] + 530
    11  UIKit                               0x00000001092451c5 -[UIViewController presentViewController:animated:completion:] + 179
    12  Registration                        0x0000000107a7208a _TFFC12Registration23LoginPageViewController17loginButtonTappedFPs9AnyObject_T_U_FTGSqV10Foundation4Data_GSqCSo11URLResponse_GSqPs5Error___T_ + 3482
    13  Registration                        0x0000000107a695fb _TTRXFo_oGSqV10Foundation4Data_oGSqCSo11URLResponse_oGSqPs5Error____XFdCb_dGSqCSo6NSData_dGSqS1__dGSqCSo7NSError___ + 203
    14  CFNetwork                           0x000000010b8756b0 __75-[__NSURLSessionLocal taskForClass:request:uploadFile:bodyData:completion:]_block_invoke + 19
    15  CFNetwork                           0x000000010b874f5c __49-[__NSCFLocalSessionTask _task_onqueue_didFinish]_block_invoke + 308
    16  Foundation                          0x0000000107b742cd __NSBLOCKOPERATION_IS_CALLING_OUT_TO_A_BLOCK__ + 7
    17  Foundation                          0x0000000107b73faf -[NSBlockOperation main] + 101
    18  Foundation                          0x0000000107b726ac -[__NSOperationInternal _start:] + 672
    19  Foundation                          0x0000000107b6e5ef __NSOQSchedule_f + 201
    20  libdispatch.dylib                   0x000000010c2600cd _dispatch_client_callout + 8
    21  libdispatch.dylib                   0x000000010c23de6b _dispatch_queue_serial_drain + 236
    22  libdispatch.dylib                   0x000000010c23eb9f _dispatch_queue_invoke + 1073
    23  libdispatch.dylib                   0x000000010c2413b7 _dispatch_root_queue_drain + 720
    24  libdispatch.dylib                   0x000000010c24108b _dispatch_worker_thread3 + 123
    25  libsystem_pthread.dylib             0x000000010c60a712 _pthread_wqthread + 1299
    26  libsystem_pthread.dylib             0x000000010c60a1ed start_wqthread + 13
)
libc++abi.dylib: terminating with uncaught exception of type NSException

请帮我找到修复方法。

提前致谢!!!

P.S。：使用iOS 10.0和Swift 3

Answer 1

stacktrace在NSURLSession上下文中显示了一些内容。您是在主线程中还是从某个工作线程中呈现ViewController？

请检查从主线程执行演示文稿调用是否成功：

DispatchQueue.main.async {
    // here your presentation call, e.g.
    self.present(controller, animated: true, completion: nil)
}

如果没有，你应该发布完整的异常（从输出窗口）和/或更多的代码（更多的区域，你提出控制器）

显示ViewController错误

1 个答案: