64位iOS设备中的UIViewControllerHierarchyInconsistency [英] UIViewControllerHierarchyInconsistency in 64 bit iOS device

问题描述

我正在开发一个iPad应用程序，它有一个视图控制器（称为ContentViewController），里面有3个不同的视图。

I am developing an iPad application which has a single view controller (called as ContentViewController) with 3 different views in it.

1. Slider view - 从底部打开，其中包含图标列表。基于选择图标，我必须在内容视图中加载视图控制器


2. 控制视图 - 屏幕左侧有几个按钮和文本


3. 容器视图 - 这涵盖了大部分屏幕，我想根据滑块中的图标选择加载视图控制器

这是我实现它的方式

在应用程序启动时（第一次），我通常在Container View中加载主视图控制器，它具有包含应用程序相关项的表视图。每个视图控制器都在导航控制器内，我在容器视图中加载该导航控制器

At application start (for the first time), I normally load home view controller in Container View, which has table view with application related items. Every view controller is inside a navigation controller and I load that navigation controller in the container view

当我在滑块视图中选择一个图标时，我正在加载一个视图控制器。

When I select a icon in the slider view, I am loading a view controller.

以下是我在名为ContentViewController的视图控制器中执行此操作的代码：

The following is the code that I implemented to do this stuff in a view controller with name ContentViewController:

- (void) itemSelected: (UIViewController *) viewController
{
   // I am storing view controller in a instance variable currentViewController. The currentViewController is declared as @property (nonatomic , strong) UIViewController *currentViewController under @interface in header file
   if(_currentViewController == nil)
   {
      // This part of code gets executed for the first time, when there is no view controller available in ContainerView
      _currentViewController = viewController;
      [self addChildViewController:_currentViewController];
      [self.containerView addSubview:_currentViewController.view];
   }
   else if(_currentViewController != viewController)
   {
       // If a view controller is already opened in Container View and when I click a icon from the slider, this par of code is getting executed
       [self addChildViewController:viewController];
       [self transitionFromViewController:_currentViewController
                      toViewController:viewController
                              duration:0
                               options:UIViewAnimationOptionTransitionNone
                            animations:^{}
                            completion:^(BOOL finished){
                                [_currentViewController removeFromParentViewController];
                                _currentViewController = viewController;
                                [_currentViewController   didMoveToParentViewController:self];
                            }
     ];        
    }
}

上面提到的代码在iPad2和iPad3上工作正常，这是32位设备。但是当我在iPad Air（64位设备）上运行此应用程序时，它在transitionFromViewController中崩溃，引发以下错误：

The code mentioned above is working fine in iPad2 and iPad3, which are 32 bit device. But when I run this application on iPad Air (64 bit device), it is crashing in transitionFromViewController throwing following error:

Terminating app due to uncaught exception 'UIViewControllerHierarchyInconsistency', reason: 'child view controller:<UINavigationController: 0x136d76130> should have parent view controller:(null) but actual parent is:<ContentViewController: 0x136d39680>'
*** First throw call stack:
(0x183642950 0x19001c1fc 0x183642890 0x186688f00 0x18661484c 0x186613ff4 0x10009a224 0x1001104c8 0x18673d798 0x1867fe234 0x186692470 0x1865fe4a4 0x1836030a8 0x183600330 0x1836006bc 0x1835416d0 0x1891ddc0c 0x186672fdc 0x100058028 0x19060faa0)
libc++abi.dylib: terminating with uncaught exception of type NSException

我尝试了各种选项，比如删除transitionFromViewController并替换为以下代码：

I tried various options like removing transitionFromViewController and replacing with following code:

    [_currentViewController willMoveToParentViewController:nil];
    [_currentViewController removeFromParentViewController];
    _currentViewController = firstView;
    [_currentViewController didMoveToParentViewController:self];

    [self addChildViewController:_currentViewController];
    [self.containerView addSubview:_currentViewController.view];

但它在最后一行[self.containerView addSubview ....]中再次崩溃，同时提到同样的错误在iPad Air上面。我不知道如何继续，我不知道为什么只有64位设备才会出现此问题。有人可以帮我这个。

But it again crashed in last line [self.containerView addSubview....] with same error mentioned above in iPad Air. I am not sure how to proceed and I don't why this issue happens only with 64 bit device. Could someone please help me on this.

提前致谢！

Vignesh

推荐答案

我可以通过更改代码来解决此问题。在前面的代码中，我将视图控制器添加为子视图控制器，并从父视图中删除了以前的视图控制器。该代码在非64位设备上运行良好，但在64位设备上运行不正常。所以我只是将视图控制器的视图添加到容器视图的子视图中，并从超级视图中删除了以前的视图控制器。以下是修改后的代码供参考：

I am able to resolve this issue by changing the code. In the previous code, I was adding the view controller as child view controller and removed previous view controller from parent view. That code was working fine in non-64 bit device, but not on 64 bit device. So I just added view controller's view into subview of the container view and removed previous view controller from super view. Here is the modified code for reference:

if(_currentViewController == nil)
{
    _currentViewController = viewController;
    [self.containerView addSubview:viewController.view];
}
else if(_currentViewController != viewController)
{
    [_currentViewController.view removeFromSuperview];
    [self.containerView addSubview:viewController.view];
    _currentViewController = viewController;
}

它适用于所有设备。

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