在分页的UIScrollView中缩放图像

我正在按照这个教程创build一个分页UIScrollView 。

这是允许使用UIScrollView分页图像的Swift代码。 但是，它有一个限制。 我无法缩放图像。

 class PagedScrollViewController: UIViewController, UIScrollViewDelegate { @IBOutlet var scrollView: UIScrollView! @IBOutlet var pageControl: UIPageControl! var pageImages: [UIImage] = [] var pageViews: [UIImageView?] = [] override func viewDidLoad() { super.viewDidLoad() // 1 pageImages = [UIImage(named:"photo1.png")!, UIImage(named:"photo2.png")!, UIImage(named:"photo3.png")!, UIImage(named:"photo4.png")!, UIImage(named:"photo5.png")!] let pageCount = pageImages.count // 2 pageControl.currentPage = 0 pageControl.numberOfPages = pageCount // 3 for _ in 0..<pageCount { pageViews.append(nil) } // 4 let pagesScrollViewSize = scrollView.frame.size scrollView.contentSize = CGSizeMake(pagesScrollViewSize.width * CGFloat(pageImages.count), pagesScrollViewSize.height) // 5 loadVisiblePages() } func loadPage(page: Int) { if page < 0 || page >= pageImages.count { // If it's outside the range of what you have to display, then do nothing return } // 1 if let pageView = pageViews[page] { // Do nothing. The view is already loaded. } else { // 2 var frame = scrollView.bounds frame.origin.x = frame.size.width * CGFloat(page) frame.origin.y = 0.0 // 3 let newPageView = UIImageView(image: pageImages[page]) newPageView.contentMode = .ScaleAspectFit newPageView.frame = frame scrollView.addSubview(newPageView) // 4 pageViews[page] = newPageView } } func purgePage(page: Int) { if page < 0 || page >= pageImages.count { // If it's outside the range of what you have to display, then do nothing return } // Remove a page from the scroll view and reset the container array if let pageView = pageViews[page] { pageView.removeFromSuperview() pageViews[page] = nil } } func loadVisiblePages() { // First, determine which page is currently visible let pageWidth = scrollView.frame.size.width let page = Int(floor((scrollView.contentOffset.x * 2.0 + pageWidth) / (pageWidth * 2.0))) // Update the page control pageControl.currentPage = page // Work out which pages you want to load let firstPage = page - 1 let lastPage = page + 1 // Purge anything before the first page for var index = 0; index < firstPage; ++index { purgePage(index) } // Load pages in our range for var index = firstPage; index <= lastPage; ++index { loadPage(index) } // Purge anything after the last page for var index = lastPage+1; index < pageImages.count; ++index { purgePage(index) } } func scrollViewDidScroll(scrollView: UIScrollView!) { // Load the pages that are now on screen loadVisiblePages() } override func didReceiveMemoryWarning() { super.didReceiveMemoryWarning() // Dispose of any resources that can be recreated. } } 

如何使图像可缩放？

Answer 1

使用https://github.com/Charles-Hsu/ScrollViewDemo中的代码解决了问题

Answer 2

您可以创build一个从UIScrollView派生的自定义类，名称为ImageScrollView ，其中有一个UIImageView 。
使用Interface Builder创build这个。 现在在页面视图数组中，您需要添加ImageScrollView而不是UIImageView ，您将实现缩放效果。