UIPageViewController 不显示其视图控制器视图

Posted 2023-03-11

【中文标题】UIPageViewController 不显示其视图控制器视图

【英文标题】：UIPageViewController does not show its view controllers views

【发布时间】：2015-03-23 05:59:07

【问题描述】：

我在 UIViewController 中有一个 UIPageViewController，我遇到了一个问题，即没有显示 pageviewcontroller 的内部视图 [尽管我确信它们是从服务器加载的]！

一些有用的说明：

UIPageViewController（称为：pageController）

外部UIViewController（称为：OfferDetailsViewController）

pageController 中的每个 viewController 的类型都是 OfferBannerPageViewController

这是我与问题相关的代码，如果您认为这有助于找到问题源，请询问任何其他代码块

一些：OfferDetailsViewController.m：

- (void)viewDidLoad 
    [super viewDidLoad];
    delegate = (AppDelegate *)[[UIApplication sharedApplication]delegate];
    if(_offerId)
    
        _offer = [[Offer alloc]init];
        [delegate setUpAConnectionToGetADetailedOffer:_offerId];
        //first: load the offer
        [self loadOffer];
        [self startTimer];
    


-(void) loadOffer
        NSMutableString * pathPattern = [NSMutableString stringWithString: @"api/Offers/"];

        [pathPattern appendString:_offerId];

        [[RKObjectManager sharedManager]getObjectsAtPath:pathPattern parameters:nil success:^(RKObjectRequestOperation *operation, RKMappingResult *mappingResult) 
            if(mappingResult)
                _offer = (Offer *)[mappingResult.array firstObject];
                //second load the offer banners images
                [self setOfferView];

                dispatch_async(dispatch_get_main_queue(), ^
                    [self loadOfferBanners];
                );

            else
            
        
        failure:^(RKObjectRequestOperation *operation, NSError *error) 
        ];


-(void)loadOfferBanners 

    _offer.OfferPannerImagesObjects = [[NSMutableArray alloc]init];

    for(int index = 0 ; index<_offer.OfferPannerImages.count ;index++)
        NSURL *imageURL =[NSURL URLWithString:_offer.OfferPannerImages[index]];
        NSData *imageData = [NSData dataWithContentsOfURL:imageURL];
        UIImage *image = [UIImage imageWithData:imageData];
        //[UIImage imageWithData:imageData];
        if(image)
            [_offer.OfferPannerImagesObjects addObject: image];
        
    
    if(_offer.OfferPannerImagesObjects.count>0)
        [self setUpOfferBanners];
    


-(void)setUpOfferBanners 

self.pageController = [[UIPageViewController alloc]initWithTransitionStyle:UIPageViewControllerTransitionStyleScroll navigationOrientation:UIPageViewControllerNavigationOrientationHorizontal options:nil];

    self.pageController.dataSource = self;
    CGRect rect = [self.pagesView bounds];
    [[self.pageController view] setFrame:CGRectMake(rect.origin.x, rect.origin.y, rect.size.width, rect.size.height)];

    OfferBannerPageViewController * initialBanner = [self viewControllerAtIndex: 0];
    [self.pageController setViewControllers:[NSArray arrayWithObjects:initialBanner, nil] direction:UIPageViewControllerNavigationDirectionForward animated:YES completion:nil ];

    [self addChildViewController:self.pageController];
    [[self pagesView] addSubview:[self.pageController view]];
    [self.pageController didMoveToParentViewController:self];

    self.pagesView.clipsToBounds=YES;
    self.pagesView.layer.cornerRadius= 6;

这里是 ViewControllerAtIndex 方法我调试它，发现索引总是，而当我在断点处停止后悬停在它上面时，我看到它的值为 0！

- (OfferBannerPageViewController *)viewControllerAtIndex:(NSUInteger)index 

    OfferBannerPageViewController *offerBannerPageViewController = [[OfferBannerPageViewController alloc] initWithNibName:@"OfferBannerPageViewController" bundle:nil];

    offerBannerPageViewController.bannerView = _offer.OfferPannerImagesObjects[index];

    offerBannerPageViewController.index = [NSNumber numberWithLong:(long)index];
    NSLog(@"____________________ [INDEX = %ld] ___________________",(long)index);

    [offerBannerPageViewController.bannerView setImage:_offer.OfferPannerImagesObjects[index]];

    return offerBannerPageViewController;

任何帮助将不胜感激，谢谢。

更新

- (NSInteger)presentationCountForPageViewController: (UIPageViewController*)pageViewController 
    // The number of items reflected in the page indicator.
    return [_offer.OfferPannerImages count];


- (NSInteger)presentationIndexForPageViewController:(UIPageViewController *)pageViewController 
    // The selected item reflected in the page indicator.
    return 0;


-(UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerAfterViewController:(UIViewController *)viewController

    NSInteger index = (long)((OfferBannerPageViewController *)viewController).index;
    if(index >= _offer.OfferPannerImagesObjects.count)
        return nil;
    
    index ++;
    return [self viewControllerAtIndex:index];


-(UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerBeforeViewController:(UIViewController *)viewController 
    NSInteger index = (long)((OfferBannerPageViewController *)viewController).index;
    if(index == 0)
        return nil;
    index--;
    return [self viewControllerAtIndex:index];

更新 2：OfferBannerPageViewController.h

@interface OfferBannerPageViewController : UIViewController
@property (strong,nonatomic) NSNumber * index;
@property (strong,nonatomic)IBOutlet UIImageView * bannerView;
@end

【参考方案1】：

对此不确定，但也许您应该使用自动调整大小的掩码来确保 OfferBannerPageViewController 的视图与父视图一起调整宽度和高度。可能会出现当你根据 superview 的 bounds 设置 pageController.view 的 frame 时，bounds 是 0 宽高，然后不调整大小。

那就试试吧：

[[self.pageController view] setFrame:CGRectMake(rect.origin.x, rect.origin.y, rect.size.width, rect.size.height)];
[[self.pageController view] setAutoresizingMask:UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight];

【参考方案2】：

您是否实现了presentationCountForPageViewController、presentationIndexForPageViewController、viewControllerBeforeViewController 和 viewControllerAfterViewController 方法？ 请给他们看。

【讨论】：

相信获取索引的时候应该使用“pageIndex”而不是“index” NSInteger index =((OfferBannerPageViewController *)viewController).pageIndex;

感谢您的努力，我不确定，因为我在 OfferBannerPageViewController 类中没有 pageIndex 属性

啊，对。看一个例子，希望你能发现你的代码有什么问题：dropbox.com/s/3ik34ydd675lu67/PageViewDemo.zip?dl=0