UIPageViewController viewControllerAfterViewController 从未调用过

Question

我有一个 UIPageViewController，我设置了一个数组作为数据源。我看到第一页很好，演示文稿计数点显示正确，但是当我尝试将拖到下一页时，没有任何反应。所以我在 viewControllerAfterViewController 和 Before 方法中设置了一些断点，并且 它们永远不会在 上被调用。 presentationCountForPageViewController 的其他数据源方法调用正常。

知道我错过了什么吗？我一直在逐行查看我在网上找到的示例，但找不到任何内容。

- (void)viewDidLoad
{
   [super viewDidLoad];

   UIPageViewController *pageController = self.pageController;
   pageController.dataSource = self;

   UIChildViewController *initialViewController = [self viewControllerAtIndex:0];
   NSArray *viewControllers = @[initialViewController];
   [pageController setViewControllers:viewControllers direction:UIPageViewControllerNavigationDirectionForward animated:YES completion:nil];

   [self addChildViewController:pageController];
   [self.view addSubview:pageController.view];
   [pageController didMoveToParentViewController:self];
  }

- (UIPageViewController *)pageController
{
   return !_pageController ? _pageController =
      ({
          UIPageViewController *value = [[UIPageViewController alloc] initWithTransitionStyle:UIPageViewControllerTransitionStyleScroll
                                                                  navigationOrientation:UIPageViewControllerNavigationOrientationHorizontal
                                                                                options:nil];
          value.view.frame = self.view.bounds;
          value;
   }) : _pageController;
}

- (UIViewController *)pageViewController:(UIPageViewController *)pa geViewController viewControllerBeforeViewController:(UIChildViewController *)viewController
{
   NSUInteger index = viewController.index;
   return (index == 0 ) ? nil : [self viewControllerAtIndex:--index];
}

- (UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerAfterViewController:(UIChildViewController *)viewController
{
   NSUInteger index = viewController.index;
   index++;
   return (index == self.myDataSourceArray.count) ? nil : [self viewControllerAtIndex:index];
}

- (UIChildViewController *)viewControllerAtIndex:(NSUInteger)index
{
   UIChildViewController *childViewController = [UIChildViewController new];
   childViewController.view.frame = self.pageController.view.bounds;
   childViewController.index = index;

   ...

   return childViewController;
}

- (NSInteger)presentationCountForPageViewController:   (UIPageViewController *)pageViewController
{
   // The number of items reflected in the page indicator.
   return self.myDataSourceArray.count;
}

- (NSInteger)presentationIndexForPageViewController:(UI PageViewController *)pageViewController
{
   // The selected item reflected in the page indicator.
   return 0;
}

Answer 1

问题是在包含封装 UIPageViewController 的 UIViewController 子类时，我忘记在父视图控制器的 viewDidLoad 中包含 addChildViewController 和 didMoveToParentViewController

[self addChildViewController:myViewController];
[self.view addSubview:myViewController.view];
[myViewControllerController didMoveToParentViewController:self];

已解决问题。

UIPageViewController viewControllerAfterViewController 从未调用过

UIPageViewController viewControllerAfterViewController never called

ios

uipageviewcontroller

uipagecontrol