UIScrollView

UIScrollView

scrollView.frame
scrollView.isPagingEnable = true
scrollView.contentSize = CGSize() //设置滚动范围
scrollView.delegate = self

pageControl.frame
pageControl.numberOfPages
pageControl.currentPage
pageControl.addTarget

@objc func PageControlDidChanged() {
  let crtPage = scrollView.currentPage
  var frame = scrollView.frame
  frame.origin.x = frame.size.width * crtPage
  frame.origin.y = 0
  
  scrollView.scrollRectToVisible(frame, animated: true)
  isPageControlUsed = true
}

func scrollViewDidScroll() {
  if(!isPageControlUsed) {
    let pageWidth = scrollView.frame.size.width
    let page = floor(scrollView.contentOffset.x - pageWidth/2)/pageWidth + 1
    pageControl.currentPage = page
  }
  
  func scrollViewDidEndDecelerating() {
    isPageControlUsed = false
  }
}