在方向更改時重新加載UIPageViewController視圖

Question

對於我正在構建的應用程序，我在UIView有一個UIPageViewController其中Transition Style = Scroll 。 每個頁面都有相同的UITableViewController類（當然使用不同的數據）。 在這一點上一切正常。

現在我想擁有UITableViewController的橫向版本或縱向版本，具體取決於設備的方向。 為此我實現了一個NSNotification ，其方法是在方向更改（orientationChanged）上調用，這也有效。 但是從這里出現問題，當改變設備的方向時，我不確定如何加載正確的UITableViewController實例。 正如你可以看到我使用的委托方法viewControllerAtIndex的的UIPageViewControllerDataSource中，我確認的viewController的橫向或縱向的版本開始。

問題是當改變設備的方向時，只有在向左/向右掃描幾頁后才加載正確的UITableViewController 。 我必須忽略一些簡單的東西，但似乎無法找到它！

我有以下代碼片段，其中我認為問題是：

- (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

每次方向更改時，您需要再次設置視圖控制器

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

Answer 2

對我來說，這個簡單的解決方

- (void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration
{
    [self.pageController.view setNeedsLayout];
}