将定时器设置为UIPageViewController

Question

我试图让UIPageViewController每隔5秒浏览一次页面。如何在Swift中做到这一点？

有什么办法可以明确地打电话给viewControllerAfterViewController？

var timer = NSTimer.scheduledTimerWithTimeInterval(5, target: self, selector: Selector("update"), userInfo: nil, repeats: true) 

    func update() -> UIViewController { 
       // can u please tell me what to add here 
    } 



func pageViewController(pageViewController: UIPageViewController, viewControllerBeforeViewController viewController: UIViewController) -> UIViewController? 
{ 

    var index = (viewController as tourViewControllerhelper).pageIndex 

    if (index == 0) || (index == NSNotFound) { 
     return viewControllerAtIndex(4) 
    } 

    index-- 
    pageCounter-- 
    return viewControllerAtIndex(index) 
} 

func pageViewController(pageViewController: UIPageViewController, viewControllerAfterViewController viewController: UIViewController) -> UIViewController? 
{ 

    var index = (viewController as tourViewControllerhelper).pageIndex 

    if (index == NSNotFound || index == 4) { 
     return viewControllerAtIndex(0) 
    } 

    index++ 
    pageCounter++ 

    return viewControllerAtIndex(index) 
} 
func viewControllerAtIndex(index: Int) -> tourViewControllerhelper? 
{ 
    if self.pageTitles == 0 || index >= self.pageTitles 
    { 
     return nil 
    } 


    // Create a new view controller and pass suitable data. 
    let pageContentViewController = tourViewControllerhelper() 

    pageContentViewController.titleText = tourTextDescription[index] 
    pageContentViewController.pageIndex = index 
    currentIndex = index 

    println("xyz") 
    return pageContentViewController 
} 

Answer 1

我想用代码保持计数器的问题是，它不占pageViewController被手动滚动以及或柜台熄灭同步。

我花了比我想象的更多的时间想出这个场景，目前有以下工作。我原以为这是苹果提供的基本功能。

• 首先，我为每个为内容创建的ViewController设置了itemIndex属性。
• 其次，查询childViewController的索引。
• 然后转到索引+ 1。

功能：

func advancePage() { 
    let pvcs = pageViewController?.childViewControllers as! [PageContentViewController] 
    let itemIndex = pvcs[0].itemIndex 
    let firstController = getItemController(itemIndex+1)! 
    let startingViewControllers = [firstController] 
    pageViewController!.setViewControllers(startingViewControllers, direction: UIPageViewControllerNavigationDirection.Forward, animated: true, completion: nil) 
} 

的getItemController（）从正常设置拍摄，看起来像：

private func getItemController(itemIndex: Int) -> PageContentViewController? { 

    if itemIndex < contentImages.count { 
     let pageItemController = self.storyboard!.instantiateViewControllerWithIdentifier("PageContentViewController") as! PageContentViewController 
     pageItemController.itemIndex = itemIndex 
     pageItemController.imageName = contentImages[itemIndex] 
     return pageItemController 
    } 

    return nil 
} 

为了记录...计时器每5秒：

private var timer: NSTimer = NSTimer() 
override func viewDidLoad() { 
    super.viewDidLoad() 
    createPageViewController() 
    timer = NSTimer.scheduledTimerWithTimeInterval(5, target: self, selector: Selector("advancePage"), userInfo: nil, repeats: true) 
}