在scrollView swift 3上的特定页面隐藏Labe

Question

我在 ViewController 上有一个 UIScrollView 和一个 UILabel。如果用户到达滚动视图的最后一页，则应隐藏标签。我怎样才能做到这一点？这是我未完成的代码：

    swipeLabel.center.x = self.view.frame.width + 30

    self.comingSoonLabel.isHidden = false

    self.scrollView.frame = CGRect(x: 0, y: 0, width: self.scrollView.frame.width, height: self.scrollView.frame.height)
    let scrollviewHeight = self.scrollView.frame.height
    let scrollviewWidth = self.scrollView.frame.width

    let imgOne = UIImageView(frame: CGRect(x: 0, y: 0, width: scrollviewWidth, height: scrollviewHeight))
    let imgTwo = UIImageView(frame: CGRect(x: scrollviewWidth, y: 0, width: scrollviewWidth, height: scrollviewHeight))
    let feedbackView = UIView(frame: CGRect(x: scrollviewWidth*4, y: 0, width: scrollviewWidth, height: scrollviewHeight))

    imgOne.image = UIImage(named: "preview1")
    imgTwo.image = UIImage(named: "preview2")

    self.scrollView.addSubview(imgOne)
    self.scrollView.addSubview(imgTwo)
    self.scrollView.addSubview(feedbackView)

    self.addChildFeedBack(feedbackView: feedbackView)

    self.scrollView.contentSize = CGSize(width: self.scrollView.frame.width * 3, height: self.scrollView.frame.height)
    self.scrollView.isPagingEnabled = true

}

func addChildFeedBack(feedbackView: UIView){
    let contestStoryboard = UIStoryboard(name: "feedback", bundle: nil)
    let testVC = contestStoryboard.instantiateViewController(withIdentifier: "FeedbackViewController") as! FeedbackViewController
    testVC.view.frame = feedbackView.bounds
    feedbackView.addSubview(testVC.view)
    self.addChildViewController(testVC)
    testVC.didMove(toParentViewController: self)

    self.comingSoonLabel.isHidden = true
}

Answer 1

您可以使用滚动视图的委托方法获取 pageNumber。

注意 - 您需要指定滚动视图的委托并同时遵守该委托。

scrollview.delegate = self //assign

class testClass: UIViewController, UIScrollViewDelegate // conform

委托

func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) {

        let pageNumber = round(scrollView.contentOffset.x / scrollView.frame.size.width)
         if pageNumber == 3{
          // hide your label here 
         }
        // do you logic related to last page
    }