Question

似乎在切换到Xcode 6和新的iOS 8 SDK后，我的UIPageViewController被破坏了。我第一次将项目加载到UIPageViewController并显示它们时似乎工作正常但是当我以编程方式转换到下一页时，页面视图控制器的子视图由于某种原因改变了大小。以下是我用来设置页面视图控制器和转换的代码：

 if (!self.coverViewController) {

    self.coverViewController = [[UIPageViewController alloc]
            initWithTransitionStyle:UIPageViewControllerTransitionStyleScroll
              navigationOrientation:UIPageViewControllerNavigationOrientationHorizontal
                            options:nil];
    self.coverViewController.edgesForExtendedLayout = UIRectEdgeAll;
    self.coverViewController.extendedLayoutIncludesOpaqueBars = YES;
    self.coverViewController.automaticallyAdjustsScrollViewInsets = NO;
  }

  NSArray* startingViewController = @[[self updatePageViewController:arc4random() % self.dataSource.numberOfItems]];
  [self.coverViewController setViewControllers:startingViewController direction:UIPageViewControllerNavigationDirectionForward animated:NO completion:nil];
  [self.coverViewController.view setClipsToBounds:YES];
  [self updateFocusAndTrainingLabel];
  [self.coverViewController.view setTranslatesAutoresizingMaskIntoConstraints:NO];
  [self addChildViewController:self.coverViewController];
  [self.coverViewController didMoveToParentViewController:self];
  [self.view addSubview:self.coverViewController.view];
  NSDictionary* views = @{@"cover":self.coverViewController.view};
  [self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"|[cover]|" options:0 metrics:nil views:views]];
  [self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|[cover]|" options:0 metrics:nil views:views]];
  [self.view layoutIfNeeded];

-(IBAction)pageForward:(id)sender {

  if (self.dataSource.numberOfItems > 1) {
    [self changePage:UIPageViewControllerNavigationDirectionForward];
  }
}

- (void)changePage:(UIPageViewControllerNavigationDirection)direction {

  int pageIndex = [self.coverViewController.viewControllers objectAtIndex:0]).pageIndex;

  if (direction == UIPageViewControllerNavigationDirectionForward) {
    pageIndex++;
  }
  else if (direction == UIPageViewControllerNavigationDirectionReverse) {
    pageIndex = pageIndex - 1;
  }

  if (pageIndex < 0) {
    pageIndex = self.coverFlowPages.count - 1;
  } else if (pageIndex >= self.coverFlowPages.count) {
    pageIndex = 0;
  }
  UIViewController *viewController = [self updatePageViewController:pageIndex];
  if (viewController == nil) {
    return;
  }

  __weak typeof(self)weakSelf = self;
  self.nextItemButton.userInteractionEnabled = NO;
  self.previousItemButton.userInteractionEnabled = NO;
  [self.coverViewController setViewControllers:@[viewController]
                                     direction:direction
                                      animated:NO
                                    completion:^(BOOL finished) {
      if (finished) {
        weakSelf.nextItemButton.userInteractionEnabled = YES;    
        weakSelf.previousItemButton.userInteractionEnabled = YES;
        [weakSelf updateLabels];
      }
  }];
}

奇怪的是，当你水平滑动以更改页面时，只有在使用pageForward时它才能正常工作：视图控制器是否会改变高度。 UIPageViewControllers高度保持不变，但我可以看到_QueueScrollView高度在转换后发生了变化。

任何帮助都会很棒！我已经看了一会儿这个问题并且无法解决问题。不确定它是iOS 8的bug还是什么？在iOS 7上完美运行

UIPageViewController在iOS 8上表现得很奇怪

0 个答案: