UIImageView捏缩放swift

11 回答

• 86

  UIImageView pinch zoom with UIScrollView || image zooming ios in swift 3 and Xcode 8 letter Youtube video URL

  设置uiscrollview在故事板中委派
  

  class PhotoDetailViewController: UIViewController, UIScrollViewDelegate {
  
      @IBOutlet weak var scrollView: UIScrollView!
      @IBOutlet weak var imgPhoto: UIImageView!
  
      override func viewDidLoad() {
  
          super.viewDidLoad()
  
          scrollView.minimumZoomScale = 1.0
          scrollView.maximumZoomScale = 6.0        
          // scrollView.delegate = self - it is set on the storyboard.
      }  
  
      func viewForZooming(in scrollView: UIScrollView) -> UIView? {
  
          return imgPhoto
      }
  

  回复于 2024-04-27T01:59:52+08:00
• 6

  我决定将imageView添加到UIScrollView . 它允许用户缩放和平移 . 这是我使用的代码 .

  为了设置我使用的最大/最小缩放：

  scrollImg.minimumZoomScale = 1.0
      scrollImg.maximumZoomScale = 10.0
  

  这是代码的其余部分 .

  var vWidth = self.view.frame.width
      var vHeight = self.view.frame.height
  
      var scrollImg: UIScrollView = UIScrollView()
      scrollImg.delegate = self
      scrollImg.frame = CGRectMake(0, 0, vWidth!, vHeight!)
      scrollImg.backgroundColor = UIColor(red: 90, green: 90, blue: 90, alpha: 0.90)
      scrollImg.alwaysBounceVertical = false
      scrollImg.alwaysBounceHorizontal = false
      scrollImg.showsVerticalScrollIndicator = true
      scrollImg.flashScrollIndicators()
  
      scrollImg.minimumZoomScale = 1.0
      scrollImg.maximumZoomScale = 10.0
  
      defaultView!.addSubview(scrollImg)
  
      imageView!.layer.cornerRadius = 11.0
      imageView!.clipsToBounds = false
      scrollImg.addSubview(imageView!)
  

  我也必须添加它

  func viewForZoomingInScrollView(scrollView: UIScrollView) -> UIView? {
      return self.imageView
  }
  

  Swift 3 & above function prototype

  func viewForZooming(in scrollView: UIScrollView) -> UIView? {
      return self.mainImage
  }
  

  回复于 2024-04-27T01:59:52+08:00
• 0

  swift 4的选项

  class ViewController: UIViewController, UIScrollViewDelegate {
  
  @IBOutlet weak var scrolView: UIScrollView!
  @IBOutlet weak var imgPhoto: UIImageView!
  
    override func viewDidLoad() {
      super.viewDidLoad()
      scrolView.delegate = self
      scrolView.minimumZoomScale = 1.0
      scrolView.maximumZoomScale = 10.0
    }
  
    func viewForZooming(in scrollView: UIScrollView) -> UIView? {
      return imgPhoto
    }
  }
  

  回复于 2024-04-27T01:59:52+08:00
• 0

  在我看来，问题是你对currentScale的确定 . 它总是等于1，因为你改变了imageView的比例 . 您应该按如下方式分配currentScale：

  let currentScale = self.imageView?.frame.size.width / self.imageView?.bounds.size.width
  

  回复于 2024-04-27T01:59:52+08:00
• 6

  您可以使用ImageScrollView开源，可缩放和可滚动的图像视图 . http://github.com/huynguyencong/ImageScrollView

  像这个开源一样，将ImageView添加到ScrollView

  open class ImageScrollView: UIScrollView {
     var zoomView: UIImageView? = nil
  }
  
  extension ImageScrollView: UIScrollViewDelegate{
  
      public func viewForZooming(in scrollView: UIScrollView) -> UIView? {
          return zoomView
      }
  
      public func scrollViewDidZoom(_ scrollView: UIScrollView) {
          adjustFrameToCenter()
      }
  }
  

  回复于 2024-04-27T01:59:52+08:00
• 0

  Swift 3解决方案

  默认情况下， UIImageView's userInteration 被禁用 . 在 UIImageView 中添加任何手势之前启用它 .

  imgView.isUserInteractionEnabled = true

  相对于屏幕坐标中两次触摸的点的比例因子

  var lastScale:CGFloat!
  func zoom(gesture:UIPinchGestureRecognizer) {
      if(gesture.state == .began) {
          // Reset the last scale, necessary if there are multiple objects with different scales
          lastScale = gesture.scale
      }
      if (gesture.state == .began || gesture.state == .changed) {
      let currentScale = gesture.view!.layer.value(forKeyPath:"transform.scale")! as! CGFloat
      // Constants to adjust the max/min values of zoom
      let kMaxScale:CGFloat = 2.0
      let kMinScale:CGFloat = 1.0
      var newScale = 1 -  (lastScale - gesture.scale)
      newScale = min(newScale, kMaxScale / currentScale)
      newScale = max(newScale, kMinScale / currentScale)
      let transform = (gesture.view?.transform)!.scaledBy(x: newScale, y: newScale);
      gesture.view?.transform = transform
      lastScale = gesture.scale  // Store the previous scale factor for the next pinch gesture call
    }
  }
  

  回复于 2024-04-27T01:59:52+08:00
• 10

  Swift 3解决方案

  这是我使用的代码 . 我将imageView添加到scrollView作为子视图 .

  class ZoomViewController: UIViewController,UIScrollViewDelegate {
  
  @IBOutlet weak var scrollView:UIScrollView!
  @IBOutlet weak var imageView:UIImageView!
  
  override func viewDidLoad() {
  
          super.viewDidLoad()
          scrollView.delegate = self
  
          scrollView.minimumZoomScale = 1.0
          scrollView.maximumZoomScale = 10.0//maximum zoom scale you want
          scrollView.zoomScale = 1.0
  
  }
  
  func viewForZooming(in scrollView: UIScrollView) -> UIView? {
          return imageView
  }
  

  回复于 2024-04-27T01:59:52+08:00
• 0

  我认为最大的问题是在 func 结束时，你有 sender.scale = 1 . 如果删除该行代码，则您的图片不应每次都反弹 .

  回复于 2024-04-27T01:59:52+08:00
• 5

  我在Swift 3中发布了一个用于缩放和双击的缩放功能的答案here . 完美无缺 .

  回复于 2024-04-27T01:59:52+08:00
• 3

  这是一个老问题，但我没有看到任何解释原始代码有什么问题的答案 .

  这一行：

  let currentScale = self.view.frame.size.width / self.view.bounds.size.width
  

  正在处理主视图而不是imageView，因此比例计算总是〜1

  这个简单的更改使其行为符合预期

  let currentScale = sender.view!.frame.size.width / sender.view!.bounds.size.width
  

  通过将self更改为发送者（以及强制视图解包），缩放计算按预期工作 .

  回复于 2024-04-27T01:59:52+08:00
• 43

  我最终到了这里，可能是以错误的方式搜寻的 .

  我在contentMode = .centre中使用了我的imageView . 但我判断它太大了，我正在寻找一种方法来缩小它 . 这是如何做：

  self.imageView.contentScaleFactor = 3
  

  1就像你在做任何事情一样 . 更多，1缩小... 3适合我，但你需要测试它 .

  回复于 2024-04-27T01:59:52+08:00