不平衡通話開始爲/終端外形的轉變：在<UIViewController中0x176c0bd0>導航控制器

Question

我想寫一個自定義賽格瑞和所遇到的這個錯誤

不平衡通話開始/結束的外觀轉變爲的UIViewController：0x176c0bd0

幫助按鈕連接到幾乎是空的ViewController - 和退出按鈕解開SEGUE

所有的控制器AR嵌入在導航控制器中。

我已經閱讀了各種帖子，在這裏人們遇到同樣的問題，但解決方案變化很大，我仍然沒有找到合適的解決方案。我認爲這是因爲我在導航控制器中調用了自定義的segue，但是我的代碼沒有反映出這一點。我已經按照本教程中創建自定義SEGUE http://blog.dadabeatnik.com/2013/10/13/custom-segues/

初始控制器具有以下方法：

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender 
{ 
    if([segue isKindOfClass:[ICIHelpSegue class]]) { 
     ((ICIHelpSegue *)segue).originatingPoint = self.help.center; 
    }  
} 

- (IBAction)unwindFromViewController:(UIStoryboardSegue *)sender { 
} 

- (UIStoryboardSegue *)segueForUnwindingToViewController:(UIViewController *)toViewController fromViewController:(UIViewController *)fromViewController identifier:(NSString *)identifier { 
    ICIUnwindHelpSegue *segue = [[ICIUnwindHelpSegue alloc] initWithIdentifier:identifier source:fromViewController destination:toViewController]; 
    segue.targetPoint = self.help.center; 
    return segue; 
} 

的ICIHelpSegue類是如下界面：

@interface ICIHelpSegue : UIStoryboardSegue 

    @property CGPoint originatingPoint; 
    @property CGPoint targetPoint; 

    @end 

和實現文件看起來像這樣：

@implementation ICIHelpSegue 
- (void)perform { 
    UIViewController *sourceViewController = self.sourceViewController; 
    UIViewController *destinationViewController = self.destinationViewController; 
    UINavigationController *navigationController = sourceViewController.navigationController; 

    [navigationController.view addSubview:destinatiionViewController.view] 

    // Transformation start scale 
    destinationViewController.view.transform = CGAffineTransformMakeScale(0.05, 0.05); 

    // Store original centre point of the destination view 
    CGPoint originalCenter = destinationViewController.view.center; 
    // Set center to start point of the button 
    destinationViewController.view.center = self.originatingPoint; 

    [UIView animateWithDuration:0.5 
          delay:0.0 
         options:UIViewAnimationOptionCurveEaseInOut 
        animations:^{ 
         // Grow! 
         destinationViewController.view.transform = CGAffineTransformMakeScale(1.0, 1.0); 
         destinationViewController.view.center = originalCenter; 
        } 
        completion:^(BOOL finished){ 
         [destinationViewController.view removeFromSuperview]; // remove from temp super view 
         [navigationController presentViewController:destinationViewController animated:NO completion:NULL]; // present VC 
        }]; 
} 

@end 

任何ide爲什麼會出現這種錯誤？這是什麼意思？以及如何解決它？

Answer 1

我有同樣的錯誤。這個問題似乎與調用presentViewController的removeFromSuperview在同一個運行循環中被調用：animated：對於相同的viewController/view完成。

有一兩件事可以做，以擺脫這種警告是延遲之後呈現視圖控制器：

completion:^(BOOL finished) 
    { 
     destinationViewController.view removeFromSuperview]; 
     [navigationController performSelector:@selector(presentViewController:) withObject:destinationViewController afterDelay:0]; 
    }]; 

} 

-(void)presentViewController:(UIViewController*)viewController 
{ 
    [[self presentViewController:viewController animated:NO completion:nil]; 
} 

然而，無論這種方法和一個與警告有時有閃爍，因爲有是一個框架，視圖已從超級視圖中刪除，但尚未顯示。

爲了解決這個問題，你可以創建目標視圖控制器的快照視圖，並添加到視圖層次結構代替實際destinationViewController的觀點，然後將其刪除後的destinationViewController已經呈現：

completion:^(BOOL finished) 
    { 
     UIView * screenshotView = [destinationViewController.view snapshotViewAfterScreenUpdates:NO]; 

     screenshotView.frame = destinationViewController.view.frame; 

     [destinationViewController.view.superview insertSubview:screenshotView aboveSubview: destinationViewController.view]; 
     [destinationViewController.view removeFromSuperview]; 

     [self performSelector:@selector(presentViewControllerRemoveView:) withObject:@[destinationViewController, screenshotView] afterDelay:0]; 


    }]; 
} 

-(void)presentViewControllerRemoveView:(NSArray *)objects 
{ 
    UIViewController * viewControllerToPresent = objects[0]; 
    UIView * viewToRemove = objects[1]; 

    [self presentViewController:viewControllerToPresent 
         animated:NO 
        completion: 
    ^{ 
     [viewToRemove removeFromSuperview]; 
    }]; 
}