在 UIScrollview 上缩放图像后，它会滚动到图像区域之外

Posted 2023-03-11

【中文标题】在 UIScrollview 上缩放图像后，它会滚动到图像区域之外

【英文标题】：After zooming image on UIScrollview, it scroll outside of image areas

【发布时间】：2016-03-04 13:11:59

【问题描述】：

我正在尝试使用UIScrollview 实现图像缩放功能。我将图像保持在合适的位置。 图像在UIScrollView 内，并且图像框架与UIScrollView 类似。 这是我的代码。

class CroppingImageViewController: UIViewController, UIScrollViewDelegate    
    var image:UIImage = UIImage()

    @IBOutlet var imageview:UIImageView!
    @IBOutlet var scrollview:UIScrollView!

    override func viewDidLoad() 
        super.viewDidLoad()

        // Do any additional setup after loading the view.
        imageview.image = image
        scrollview.contentSize = imageview.frame.size;
        scrollview.minimumZoomScale = 1.0;
        scrollview.maximumZoomScale = 4.0;
        scrollview.setZoomScale(scrollview.minimumZoomScale, animated: true)
        scrollview.delegate = self;
    

    func viewForZoomingInScrollView(scrollView: UIScrollView) -> UIView? 
        return imageview
    
  

What's actually happeningWhat required 我的要求是图像应该向上滚动到它的内容。

【参考方案1】：

self.automaticallyAdjustsScrollViewInsets=NO;

根据苹果文档，automaticAdjustScrollViewInsets 默认为 YES。

所以它试图控制你的滚动视图。

将此添加到您的 viewdidload 方法中，然后尝试。

【讨论】：

还是一样。不走运！！

【参考方案2】：

我一直在寻找同样的东西。我确实喜欢这个。它对我有用。

    func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) 
        let image = info[UIImagePickerControllerOriginalImage] as! UIImage
        imageView.image = image

        imageView.contentMode = UIViewContentMode.center
        imageView.frame = CGRect(x: 0, y: 0, width: image.size.width, height: image.size.height)

        ScrollView.contentSize = imageView.frame.size

        let scrollViewFrame = ScrollView.frame
        let scaleWidth = scrollViewFrame.size.width / ScrollView.contentSize.width
        let scaleHeight = scrollViewFrame.size.height/ScrollView.contentSize.height

        let minScale = min(scaleHeight, scaleWidth)

        ScrollView.minimumZoomScale = minScale
        ScrollView.maximumZoomScale = 1
        ScrollView.zoomScale = minScale
        ScrollView.clipsToBounds = true

        centerScrollViewContents()

        picker.dismiss(animated: true, completion: nil)

    

 func centerScrollViewContents()
    let boundsSize = ScrollView.bounds.size
        var contentsFrame = imageView.frame

        if contentsFrame.size.width < boundsSize.width
            contentsFrame.origin.x = (boundsSize.width - contentsFrame.size.width)/2

        else
            contentsFrame.origin.x = 0
        

        if contentsFrame.size.height < boundsSize.height
            contentsFrame.origin.y = (boundsSize.height - contentsFrame.size.height)/2
        else
            contentsFrame.origin.y = 0
        

        imageView.frame = contentsFrame