UIPageViewController 和景观

Question

我一直在尝试以下操作，但没有任何效果，

NSDictionary *pageViewOptions = [NSDictionary dictionaryWithObjectsAndKeys:UIPageViewControllerOptionSpineLocationKey, [NSNumber numberWithInteger:UIPageViewControllerSpineLocationMid],nil];
NSLog(@"pageViewOptions :%@",pageViewOptions);    

self.pageViewController = [[UIPageViewController alloc] initWithTransitionStyle:UIPageViewControllerTransitionStylePageCurl navigationOrientation:UIPageViewControllerNavigationOrientationHorizontal options:pageViewOptions];    
NSLog(@"spineLocation :%d",self.pageViewController.spineLocation);

pageViewOptions 处的 NSlog 为 2，spineLocation 处的 NSlog 为 1。这让我陷入困境，我想做的就是在中间使用脊柱进行初始化。它总是在左侧初始化。该应用程序在横向模式下初始化，但仅在将设备旋转 180 度后才执行该方法 “- (UIPageViewControllerSpineLocation)pageViewController:(UIPageViewController *)pageViewController spinLocationForInterfaceOrientation:(UIInterfaceOrientation)orientation” 有效，然后我的脊柱就在中间了。有人可以解释一下吗？我到处寻找答案。

我想要它做的就是在横向中初始化，中间有一个脊柱

Answer 1

尝试使用“options”参数：

NSDictionary *options = (UIInterfaceOrientationIsLandscape(self.interfaceOrientation)) ? [NSDictionary dictionaryWithObject: [NSNumber numberWithInteger:UIPageViewControllerSpineLocationMid] forKey: UIPageViewControllerOptionSpineLocationKey] : nil; 

self.pageViewController = [[UIPageViewController alloc] initWithTransitionStyle:UIPageViewControllerTransitionStylePageCurl navigationOrientation:UIPageViewControllerNavigationOrientationHorizontal options:options];

...

并且不要忘记初始化 2 个内容视图控制器：

NSArray *viewControllers = [NSArray arrayWithObjects:contentViewController1, contentViewController2, nil];

[self.pageViewController setViewControllers:viewControllers direction:UIPageViewControllerNavigationDirectionForward animated:NO completion:nil];