UIImageView在UIScrollView中缩放和缩小 [英] UIImageView zoom and pinch in UIScrollView

问题描述

我尝试了许多不同的方法来实现扩展图像和缩小缩放.我找到了有关如何使用保存在项目中的图像执行此操作的教程，但是我正在从Firebase检索图像.我希望一幅图像占据ProfileViewController屏幕的一半左右，另一幅图像能够被放大为整页，并且还具有缩放功能.我现在拥有的代码可以执行此操作，但是缩放和位置不干净或不易于使用.

I have tried many different ways of implementing expand image and pinch to zoom. I have found tutorials on how to do this with images saved in my project however I am retrieving my images from Firebase. I would like one image to take about half the ProfileViewController screen and the other pictures to be able to be expanded full page and also have the ability to zoom. My code I have for it now does this however the zooming and the position is not clean or easy to use.

var newImageView: UIImageView!



@IBAction func imageTapped(_ sender: UITapGestureRecognizer)  {
    let imageView = sender.view as! UIImageView

    let scrollView = UIScrollView(frame: self.view.frame)


    newImageView = UIImageView(image: imageView.image)
    newImageView.frame = self.view.frame
    newImageView.backgroundColor = .black
    newImageView.contentMode = .top
    newImageView.isUserInteractionEnabled = true


    let tap = UITapGestureRecognizer(target: self, action: #selector(dismissFullscreenImage))
    scrollView.addGestureRecognizer(tap)


    scrollView.delegate = self
    scrollView.minimumZoomScale = 1.0
    scrollView.maximumZoomScale = 3.0

    scrollView.addSubview(newImageView)

    self.view.addSubview(scrollView)
}

func viewForZooming(in scrollView: UIScrollView) -> UIView?
{
    return newImageView;
}

func dismissFullscreenImage(_ sender: UITapGestureRecognizer) {
    sender.view?.removeFromSuperview()
}

推荐答案

在这里，我正在以编程方式创建滚动视图和图像视图，在这里 img 是PHAsset，我正在从图库中选择图像.

Here is I am creating scrollview and imageview programatically and here img is a PHAsset that I am selecting image from gallery.

这是我在做什么，选择一个图像并移至其他视图控制器，然后根据我的imageview调整该图像的大小 因此，缩放后图像不会模糊.

最小缩放是imageview的边界，最大缩放是4.0.

Here what I am doing, select an image and move to other view controller and I resize that image according to my imageview So image is not blurry after zooming it.

Minimum zooming is imageview bound and maxmimum zooming is 4.0.

func singleVC1()  {
        let v = UIView(frame: CGRect(x: 40, y: 50, width: self.view.frame.size.width - 80, height: view.frame.size.height - 200))
        let view1 = UIView(frame: CGRect(x: 0, y: 0, width: v.frame.size.width, height: v.frame.size.height/2 - 1))
        let scroll1 = UIScrollView.init(frame: view1.bounds)
        let imgview = UIImageView.init(frame: (CGRect)(origin: CGPoint.zero, size: self.returnAspectSize(targetWidth: view.frame.size.width, img: img)))
        self.setZoomScale(scrollview: scroll1, imageview: imgview)
        imgview.image = self.getUIImage(asset: img)
        scroll1.maximumZoomScale = 4.0;
        scroll1.delegate = self;
        scroll1.bounces = false
        scroll1.contentSize =  imgview.frame.size
        scroll1.addSubview(imgview)
        view1.layer.borderColor = UIColor.red.cgColor
        view1.layer.borderWidth = 5.0
        view1.addSubview(scroll1)
        v.addSubview(view1)

        let view2 = UIView(frame: CGRect(x: 0, y: v.frame.size.height/2+1, width: v.frame.size.width, height: v.frame.size.height/2 - 1))
        let scroll2 = UIScrollView.init(frame: view2.bounds)
        let imgview1 = UIImageView.init(frame: (CGRect)(origin: CGPoint.zero, size: self.returnAspectSize(targetWidth: view.frame.size.width, img: img)))
        imgview1.image = self.getUIImage(asset: img)
        self.setZoomScale(scrollview: scroll2, imageview: imgview1)
        scroll2.bounces = false

        scroll2.maximumZoomScale = 4.0;
        scroll2.delegate = self;
        view2.layer.borderColor = UIColor.red.cgColor
        view2.layer.borderWidth = 5.0
        scroll2.contentSize = imgview1.frame.size
        scroll2.addSubview(imgview1)
        view2.addSubview(scroll2)
        v.addSubview(view2)
        self.view.addSubview(v)
    }
func setZoomScale(scrollview : UIScrollView, imageview : UIImageView) {
        var minZoom = min(self.view.bounds.size.width / imageview.bounds.size.width, self.view.bounds.size.height / imageview.bounds.size.height);

        if (minZoom > 1.0) {
            minZoom = 1.0;
        }
        scrollview.minimumZoomScale = minZoom;
        scrollview.zoomScale = minZoom;
    }
    func returnAspectSize(targetWidth : CGFloat, img : PHAsset) -> CGSize {
        let img1 = self.getUIImage(asset: self.img)
        let targetwidth = targetWidth
        let scalefactor = (CGFloat)(targetwidth) / (CGFloat)((img1?.size.width)!)
        let targetheight = (img1?.size.height)! * scalefactor
        let targesize = CGSize(width: (CGFloat)(targetwidth), height: targetheight)
        return targesize
    }

尝试一下.我相信这会对您有所帮助.

Try this. I am sure this will help you.

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