2017-06-16 71 views

回答

1

请试试这个,

func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) { 
     let row = scrollView.contentOffset.x/cellWidth 
     currentIndexShown = Int(row) 

    } 

    func scrollViewDidScroll(_ scrollView: UIScrollView) { 

     if scrollView.contentOffset.x < cellWidth * CGFloat(currentIndexShown){ 
      scrollView.contentOffset = CGPoint(x: cellWidth * CGFloat(currentIndexShown), y: -20) 
      scrollView.bounces = false 
     } else { 
      scrollView.bounces = true 
     } 
}