如何使用 UIScrollView 实现 UIPageViewController？

我拿了照片滚动来自苹果网站的示例，并尝试通过复制代码来实现我自己的专辑。现在UIScrollView不可见。我该如何让它出现？

我所做的唯一代码更改是创建UIPageViewController。就我而言，这是一个UIViewController这是打开它而不是AppDelegate.

@implementation BasePhotoViewController

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nil bundle:nibBundleOrNil];
    if (self) {
        // kick things off by making the first page

        PhotoViewController *pageZero = [PhotoViewController photoViewControllerForPageIndex:0];
        if (pageZero != nil)
        {
            // assign the first page to the pageViewController (our rootViewController)
            //UIPageViewController *pageViewController = (UIPageViewController *)    [[UIApplication sharedApplication] keyWindow].rootViewController;
            UIPageViewController *pageViewController = [[UIPageViewController alloc] initWithTransitionStyle:0 navigationOrientation:0 options:nil];
            //UIPageViewController *pageViewController = (UIPageViewController *)self.parentViewController;
            pageViewController.dataSource = self;

            [pageViewController setViewControllers:@[pageZero]
                                     direction:UIPageViewControllerNavigationDirectionForward
                                      animated:NO
                                    completion:NULL];
        }
    }
    return self;
}

您没有添加pageViewController的视图作为子视图BasePhotoViewController的观点。你的BasePhotoViewController类应该看起来像这样。请注意中的代码viewDidLoad.

BasePhotoViewController.h：

@interface BasePhotoViewController : UIViewController <UIPageViewControllerDataSource>
@property (nonatomic, strong) UIPageViewController * pageViewController;
@end

BasePhotoViewController.m：

#import "BasePhotoViewController.h"
#import "PhotoViewController.h"

@implementation BasePhotoViewController

@synthesize pageViewController;

- (id)initWithCoder:(NSCoder *)coder
{
    self = [super initWithCoder:coder];
    if (self) {
        PhotoViewController *pageZero = [PhotoViewController photoViewControllerForPageIndex:0];
        if (pageZero != nil)
        {
            self.pageViewController = [[UIPageViewController alloc] initWithTransitionStyle:0
                                                                      navigationOrientation:0
                                                                                    options:nil];
            self.pageViewController.dataSource = self;

            [self.pageViewController setViewControllers:@[pageZero]
                                              direction:UIPageViewControllerNavigationDirectionForward
                                               animated:NO
                                             completion:NULL];
        }
    }
    return self;
}

- (void)viewDidLoad
{
    [super viewDidLoad];

    [self addChildViewController:self.pageViewController];
    [self.view addSubview:self.pageViewController.view];
    [self.pageViewController didMoveToParentViewController:self];
}

# pragma mark - UIPageViewControllerDataSource

- (UIViewController *)pageViewController:(UIPageViewController *)pvc viewControllerBeforeViewController:(PhotoViewController *)vc
{
    NSUInteger index = vc.pageIndex;
    return [PhotoViewController photoViewControllerForPageIndex:(index - 1)];
}

- (UIViewController *)pageViewController:(UIPageViewController *)pvc viewControllerAfterViewController:(PhotoViewController *)vc
{
    NSUInteger index = vc.pageIndex;
    return [PhotoViewController photoViewControllerForPageIndex:(index + 1)];
}

@end

Note:我已经初始化了UIPageViewController in initWithCoder:因为苹果的照片滚动代码使用故事板。我删除了UIPageViewController从故事板中创建了一个BasePhotoViewController在它的位置。如果您没有加载BasePhotoViewController从故事板中，您应该将代码移入initWithCoder:到适当的初始化程序。

EDIT:看到这个示例项目在 github 上。