//翻页动画执行完成后回调的方法
- (void)pageViewController:(UIPageViewController *)pageViewController didFinishAnimating:(BOOL)finished previousViewControllers:(NSArray<UIViewController *> *)previousViewControllers transitionCompleted:(BOOL)completed;
//屏幕防线改变时回到的方法，可以通过返回值重设书轴类型枚举
- (UIPageViewControllerSpineLocation)pageViewController:(UIPageViewController *)pageViewController spineLocationForInterfaceOrientation:(UIInterfaceOrientation)orientation;
注：相关教程知识阅读请移步到IOS开发频道。
