在容器视图控制器中旋转UIPageViewController

Question

我有一个包含其他ViewControllers的UIViewController.初始ViewController在viewDidLoad中设置:

FirstViewController *first = [FirstViewController alloc] init];
first.view.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
first.view.frame = m_content.frame;

[self addChildViewController:first];
[m_content.view addSubview:first.view];
[first didMoveToParentViewController:self];
m_activeViewController = first;

此Container Controller已实现automaticForwardAppearanceAndRotationMethodsToChildViewControllers返回YES.它还实现了手动将旋转更改转发到非活动ViewControllers

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
    return YES;
}
- (void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration
{
    for(UIViewController *vc in m_viewControllers)
    {
        if(vc != [m_activeViewController]
            [vc willRotateToInterfaceOrientation:toInterfaceOrientation duration:duration];
    }
}
- (void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation
{
    for(UIViewController *vc in m_viewControllers)
    {
        if(vc != [m_activeViewController]
            [vc didRotateFromInterfaceOrientation:fromInterfaceOrientation];
    }
}

当点击菜单按钮时,我在ViewControllers之间进行转换.

- (void)onMenuItemTapped:(id)sender
{
    UIViewController *vc = [m_viewControllers objectAtIndex:sender.tag];

    vc.view.frame = m_content.frame;
    [self addChildViewController:vc];
    [self transitionFromViewController:m_activeViewController toViewController:vc duration:0 options:UIViewAnimationOptionTransitionNone animations:nil completion:^(BOOL finished) {
    [vc didMoveToParentViewController:self];
    [m_activeViewController removeFromParentViewController];
    m_activeViewController = vc;
    }];
}

此转换适用于我的"普通"ViewControllers,它们在方向更改后正确显示,即使它们未处于活动状态.但是,其中一个名为SecondCV 的子视图控制器将UIPageViewController作为子视图控制器.我将UIPageViewControllerDelegate和UIPageViewControllerDataSource设置为此SecondCV并在pageViewController中:spineLocationForInterfaceOrientation:我为Portrait返回UIPageViewControllerSpineLocationMin,为Landscape返回UIPageViewControllerSpineLocationMid.此活动的旋转在活动时正常工作 - 横向上有两个页面,纵向模式上有一个页面正确显示.但是当此SecondVC未激活时,旋转不正确.即使调用了pageViewController:spineLocationForInterfaceOrientation : ,在纵向和横向模式下仍然有一个页面.我试图解决这个问题一段时间,但我没有看到任何其他选择.你有任何想法如何解决这个问题？

谢谢.

Answer 1

我已经解决了这种棘手的问题。

实际上，SecondVC 已正确旋转，或者至少，脊柱位置已正确更改。因此，当我旋转设备并且 SecondVC 在父视图中不是活动视图控制器时，它已收到旋转消息并且pageViewController:spineLocationForInterfaceOrientation:也被调用。我为新的界面方向设置了正确的书脊位置，并将setViewControllers调用到 SecondVC 的页面视图控制器。问题是，即使我为UIPageViewControllerSpineLocationMid设置两个视图控制器，在显示 SecondVC 后仍然只有一个，就像 UIPageViewControllerSpineLocationMin 中一样。

我已经“修复”了这个问题，通过将视图控制器设置为viewWillAppear:中的页面视图控制器，因为当调用此方法时，页面视图控制器的书脊位置是正确的，并且根据此信息我设置了一个或两个页面（视图控制器）

- (void)viewWillAppear:(BOOL)animated
{
if(m_pageController.spineLocation == UIPageViewControllerSpineLocationMid)
{
    LeftPageController *left;
    RightPageController *right;
    if(m_pageController.viewControllers.count > 0)
    {
        left = [m_pageController.viewControllers objectAtIndex:0];

        right = [m_storyboard instantiateViewControllerWithIdentifier:@"rightPage"];
        [right loadView];
    }

    [m_pageController setViewControllers:[NSArray arrayWithObjects:left, right, nil] direction:UIPageViewControllerNavigationDirectionForward | UIPageViewControllerNavigationDirectionReverse animated:NO completion:nil];

    [m_left hideGallery];
}

if(m_pageController.spineLocation == UIPageViewControllerSpineLocationMin)
{

    [m_pageController setViewControllers:[NSArray arrayWithObject:[m_pageController.viewControllers objectAtIndex:0]] direction:UIPageViewControllerNavigationDirectionForward | UIPageViewControllerNavigationDirectionReverse animated:NO completion:nil];
}

[super viewWillAppear:animated];
}


- (UIPageViewControllerSpineLocation)pageViewController:(UIPageViewController *)pageViewController spineLocationForInterfaceOrientation:(UIInterfaceOrientation)orientation
{
if(UIInterfaceOrientationIsPortrait(orientation))
{
    LeftPageController *left = [pageViewController.viewControllers objectAtIndex:0];
    [pageViewController setViewControllers:[NSArray arrayWithObject:left] direction:UIPageViewControllerNavigationDirectionForward | UIPageViewControllerNavigationDirectionReverse animated:NO completion:nil];

    pageViewController.doubleSided = NO;     

    return UIPageViewControllerSpineLocationMin;
}

if(UIInterfaceOrientationIsLandscape(orientation))
{    
    LeftPageController *left;
    RightPageController *right;
    if(pageViewController.viewControllers.count > 0)
    {
        left = [pageViewController.viewControllers objectAtIndex:0];
        right = [m_storyboard instantiateViewControllerWithIdentifier:@"rightPage"];
        [right loadView];
    }

    [pageViewController setViewControllers:[NSArray arrayWithObjects:left,right, nil] direction:UIPageViewControllerNavigationDirectionForward | UIPageViewControllerNavigationDirectionReverse animated:NO completion:nil];

    return UIPageViewControllerSpineLocationMid;
}

return UIPageViewControllerSpineLocationMin;
}

我知道我做了两次同样的事情，但这就是我在这种情况下愿意付出的代价。为什么在调用pageViewController:spineLocationForInterfaceOrientation:并为 Landscape 设置两个视图控制器后，当 SecondVC 处于非活动状态时，激活 SecondVC 后，在viewWillAppear:中的 m_pageController 中只有一个 ViewController对我来说仍然是个谜。