UIPageViewController转换'不平衡调用开始/结束外观转换' [英] UIPageViewController transition 'Unbalanced calls to begin/end appearance transitions for '

问题描述

当我浏览 UIPageViewController 比其转换动画更快时，我得到'对< MyDataViewController> <的开始/结束外观转换的非平衡调用'并且直到我尝试翻页时才会显示横向中的两个视图之一。

任何人都有想法解决此错误？

解决方案

按照以下步骤解决：

1-声明一个标志，表示动画已完成与否：

  BOOL pageAnimationFinished; 
  

2-在viewDidLoad中将此标志设置为true：

  pageAnimationFinished = YES; 
  

3-禁用pageViewController的tapGesture并将'self'指定给panGestureRecognizer委托：

'pre> 为（UIGestureRecognizer * gesRecog在self.pageViewController.gestureRecognizers）
{
如果（[gesRecog isKindOfClass：[UITapGestureRecognizer类] ]）
gesRecog.enabled = NO;
else if（[gesRecog isKindOfClass：[UIPanGestureRecognizer class]]）
gesRecog.delegate = self;
}


4-通过以下手势识别器委托方法允许/禁止panGestureRecognizer：

   - （BOOL）gestureRecognizerShouldBegin：（UIGestureRecognizer *）gestureRecognizer 
 {
如果（[gestureRecognizer isKindOfClass：[UIPanGestureRecognizer类]&安培;及（[gestureRecognizer.view isEqual：方法self.view] || [gestureRecognizer.view isEqual：方法self.pageViewController.view]））
 {
 UIPanGestureRecognizer *庞热=（UIPanGestureRecognizer * ）gestureRecognizer; 
 if（！pageAnimationFinished ||（currentPage< minimumPage&& [panGes velocityInView：self.view] .x< 0）||（currentPage> maximumPage&& [panGes velocityInView：self。查看] .x> 0））
返回NO; 
 pageAnimationFinished = NO; 
} 
返回YES; 
} 
  

5-添加以下pageViewController委托方法：

'pre> - （无效）pageViewController：（UIPageViewController *）pageViewController didFinishAnimating：（BOOL）完成previousViewControllers：（NSArray的*）previousViewControllers transitionCompleted：（BOOL）完成了
{
pageAnimationFinished = YES;
}


When I navigate through UIPageViewController faster than its transition animation I am getting 'Unbalanced calls to begin/end appearance transitions for <MyDataViewController>' and one of the two views in landscape isn't shown until I try to turn the page.

Anybody has an idea to solve this bug?

解决方案

Solved following these steps:
1- Declare a flag to indicate that the animation has finished or not:

BOOL pageAnimationFinished;

2- Set this flag to true in viewDidLoad:

pageAnimationFinished = YES;

3- Disable tapGesture for the pageViewController and assign 'self' to panGestureRecognizer delegate:

for (UIGestureRecognizer * gesRecog in self.pageViewController.gestureRecognizers)
{
    if ([gesRecog isKindOfClass:[UITapGestureRecognizer class]])
        gesRecog.enabled = NO;
    else if ([gesRecog isKindOfClass:[UIPanGestureRecognizer class]])
        gesRecog.delegate = self;
}

4- Allow/Disallow panGestureRecognizer through the following gesture recognizer delegate method:

-(BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer
{
    if ([gestureRecognizer isKindOfClass:[UIPanGestureRecognizer class]] && ([gestureRecognizer.view isEqual:self.view] || [gestureRecognizer.view isEqual:self.pageViewController.view]))
    {
        UIPanGestureRecognizer * panGes = (UIPanGestureRecognizer *)gestureRecognizer;
        if(!pageAnimationFinished || (currentPage < minimumPage && [panGes velocityInView:self.view].x < 0) || (currentPage > maximumPage && [panGes velocityInView:self.view].x > 0))
            return NO;
        pageAnimationFinished = NO;
    }
    return YES;
}

5- Add the following pageViewController delegate method:

- (void)pageViewController:(UIPageViewController *)pageViewController didFinishAnimating:(BOOL)finished previousViewControllers:(NSArray *)previousViewControllers transitionCompleted:(BOOL)completed
{
    pageAnimationFinished = YES;
}

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