IOS:通过PageViewController显示WebView

Question

在我的项目中，我使用 UIPageViewController 在主页上显示一段视频。为了显示视频，我在 UIPageViewController 上使用了 UIWebView。最初我在上面使用 UIImageView 并且它工作正常但是当我应用 UIWebView 时它给出了错误:

*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[__NSPlaceholderArray initWithObjects:count:]: attempt to insert nil object from objects[0]'

请帮我解决这个问题我正在分享我的代码:

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.

    // Create the data model
    //_pageTitles = @[@"Over 200 Tips and Tricks", @"Discover Hidden Features", @"Bookmark Favorite Tip", @"Free Regular Update"];
    //_pageImages = @[@"https://www.youtube.com/embed/uObzRhWq7tk", @"Radio_Button-512.png", @"page3.png", @"page4.png"];

    _videourl = @[@"https://www.youtube.com/embed/uObzRhWq7tk",@"https://www.youtube.com/embed/38DZgGjaPOA"];


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

    PageContentViewController *startingViewController = [self viewControllerAtIndex:0];
    NSArray *viewControllers = @[startingViewController];
    [self.pageViewController setViewControllers:viewControllers direction:UIPageViewControllerNavigationDirectionForward animated:YES completion:nil];

    // Change the size of page view controller
    self.pageViewController.view.frame = CGRectMake(0, CGRectGetMaxY(searchbtn.frame)+80, self.view.frame.size.width, self.view.frame.size.height/3);

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

和

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

    // Create a new view controller and pass suitable data.
    PageContentViewController *pageContentViewController = [self.storyboard instantiateViewControllerWithIdentifier:@"PageContentViewController"];
    pageContentViewController.imageFile = self.pageImages[index];
    pageContentViewController.titleText = self.pageTitles[index];
    pageContentViewController.urlFile = self.videourl[index];


    pageContentViewController.pageIndex = index;

    return pageContentViewController;
}

Answer 1

错误表明您正在尝试将 nil 插入数组。在此行之前设置一个断点:

 NSArray *viewControllers = @[startingViewController];

startingViewController 可能是 nil。