如何用 UIScrollView 实现 UIPageViewController？

Posted 2023-03-16

【中文标题】如何用 UIScrollView 实现 UIPageViewController？

【英文标题】：How to implement UIPageViewController with a UIScrollView?

【发布时间】：2013-06-18 14:39:31

【问题描述】：

我从 Apple 的网站上获取了 Photo Scroller 示例，并尝试通过复制代码来实现我自己的相册。现在，UIScrollView 不可见。我如何让它出现？

我所做的唯一代码更改是创建UIPageViewController。就我而言，打开它的是UIViewController，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;

【参考方案1】：

您没有将pageViewController 的视图添加为BasePhotoViewController 的视图的子视图。你的BasePhotoViewController 类应该是这样的。注意viewDidLoad中的代码。

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

注意：我在initWithCoder: 中初始化了UIPageViewController，因为Apple 的Photo Scroller 代码使用故事板。我从情节提要中删除了UIPageViewController，并在其位置创建了BasePhotoViewController。如果您没有从情节提要加载BasePhotoViewController，则应将initWithCoder: 中的代码移动到适当的初始化程序。

编辑：请参阅 github 上的 sample project。