在方向更改时重新加载UIPageViewController视图

Question

对于一个应用程序我建设,我有一个UIPageViewController里面UIView有Transition Style = Scroll.每个页面都具有相同的UITableViewController类(当然具有不同的数据).在这一点上一切正常.

现在我希望拥有横向版本或纵向版本,UITableViewController具体取决于设备的方向.为此我实现了NSNotification一个方法被调用方向更改(orientationChanged),这也有效.但是从这里出现问题,当改变设备的方向时我不知道如何加载正确的UITableViewController实例.正如你可以看到我使用的委托方法viewControllerAtIndex中的UIPageViewControllerDataSource中,我确认的viewController的横向或纵向的版本开始.

问题是当改变设备的方向时,UITableViewController只有在向左/向右扫描几页之后才加载正确的.我必须忽略一些简单的东西,但似乎无法找到它!

我有以下代码片段,其中我认为问题是:

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Create the data model
    _pageTitles = @[@"1",@"2",@"3",@"4",@"5"];
    _pageTables = @[@"test1",@"test2",@"test3",@"test4",@"test5"];

    // Create page view controller
    self.weightPageViewController = [self.storyboard instantiateViewControllerWithIdentifier:@"WeightPageViewController"];
    self.weightPageViewController.dataSource = self;

    WeightPageContentViewController *startingViewController = [self viewControllerAtIndex:0];
    NSArray *viewControllers = @[startingViewController];
    [self.weightPageViewController setViewControllers:viewControllers direction:UIPageViewControllerNavigationDirectionForward animated:NO completion:nil];

    [self addChildViewController:_weightPageViewController];
    [self.view addSubview:_weightPageViewController.view];
    [self.weightPageViewController didMoveToParentViewController:self];

    self.edgesForExtendedLayout = UIRectEdgeNone;

    //Register for device orientation changes.
    [[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(orientationChanged:) name:@"UIDeviceOrientationDidChangeNotification" object:nil];
}

- (void) orientationChanged:(id)object {
    [self viewControllerAtIndex:0];
}

- (WeightPageContentViewController *)viewControllerAtIndex:(NSUInteger)index
{
    if (([self.pageTitles count] == 0) || (index >= [self.pageTitles count])) {
        return nil;
    }

    UIDeviceOrientation deviceOrientation = [UIDevice currentDevice].orientation;
    if (UIDeviceOrientationIsLandscape(deviceOrientation)) {
        NSLog(@"Orientation is now Landscape);
        // Create a new view controller and pass suitable data.
        WeightPageContentViewController *weightPageContentViewController = [self.storyboard instantiateViewControllerWithIdentifier:@"WeightPageContentViewControllerLandscape"];
        weightPageContentViewController.tableText = self.pageTables[index];
        weightPageContentViewController.titleText = self.pageTitles[index];
        weightPageContentViewController.pageIndex = index;
        return weightPageContentViewController;
    } else if (deviceOrientation == UIDeviceOrientationPortrait) {
        NSLog(@"Orientation is now Portrait);
        // Create a new view controller and pass suitable data.
        WeightPageContentViewController *weightPageContentViewController = [self.storyboard instantiateViewControllerWithIdentifier:@"WeightPageContentViewController"];
        weightPageContentViewController.tableText = self.pageTables[index];
        weightPageContentViewController.titleText = self.pageTitles[index];
        weightPageContentViewController.pageIndex = index;
        return weightPageContentViewController;
    } else {
        NSLog(@"Orientation is now unknown);
        // Create a new view controller and pass suitable data.
        WeightPageContentViewController *weightPageContentViewController = [self.storyboard instantiateViewControllerWithIdentifier:@"WeightPageContentViewController"];
        weightPageContentViewController.tableText = self.pageTables[index];
        weightPageContentViewController.titleText = self.pageTitles[index];
        weightPageContentViewController.pageIndex = index;
        return weightPageContentViewController;
    }
}

Answer 1

每次方向更改时,您需要再次设置视图控制器

WeightPageContentViewController *startingViewController = [self viewControllerAtIndex:currentViewControllerIndex];
NSArray *viewControllers = @[startingViewController];
[self.weightPageViewController setViewControllers:viewControllers direction:UIPageViewControllerNavigationDirectionForward animated:NO completion:nil];