Question

编辑：我已更新了问题代码，以便现在可以帮助任何人。

我在scrollView中有一个UICollectionViewCell，但无法通过捏合在模拟器中使用缩放功能。我可以通过手动缩放视图来实现这一点，但是当用户捏缩放时我需要将图像视图框更改为完整尺寸。现在它的大小填充框架宽度设置为屏幕宽度和框架高度设置为屏幕高度。我需要动态地将帧宽更改为等于帧高，因为图像是方形的。

这是我的代码：

import UIKit

class MyCollectionViewCell: UICollectionViewCell, UIScrollViewDelegate {

    let screenWidth = UIScreen.main.bounds.width

    let activityIndicator: UIActivityIndicatorView = {
        let spinner = UIActivityIndicatorView()
        spinner.activityIndicatorViewStyle = .white
        spinner.color = Constants.APP_SPINNER_COLOR
        spinner.hidesWhenStopped = true
        return spinner
    }()

    var zoomScrollView: UIScrollView = {
        let scrollView = UIScrollView()
        scrollView.backgroundColor = .white
        scrollView.minimumZoomScale = 1.0
        scrollView.maximumZoomScale = 6.0
        scrollView.clipsToBounds = true
        scrollView.isUserInteractionEnabled = true
        scrollView.translatesAutoresizingMaskIntoConstraints = false
        return scrollView
    }()

    var itemImageView: UIImageView = {
        let imageView = UIImageView()
        imageView.contentMode = .scaleAspectFit
        imageView.translatesAutoresizingMaskIntoConstraints = false
        imageView.backgroundColor = .white
        imageView.isUserInteractionEnabled = true
        return imageView
    }()

    func viewForZooming(in zoomScrollView: UIScrollView) -> UIView? {
        return itemImageView
    }

    override init(frame: CGRect) {
        super.init(frame: frame)

        zoomScrollView.delegate = self

        contentView.backgroundColor = .white

        contentView.addSubview(zoomScrollView)

        zoomScrollView.addSubview(itemImageView)

        itemImageView.addSubview(activityIndicator)


    zoomImageView.frame = CGRect(x:0, y:0, width: screenWidth, height: screenHeight)

    zoomScrollView.frame = itemImageView.frame

        activityIndicator.anchorCenterXToSuperview()
        activityIndicator.anchorCenterYToSuperview()    
    }

    required init?(coder aDecoder: NSCoder) {
            fatalError("init(coder:) has not been implemented")
        }
}

Answer 1

您需要设置捏缩放的scrollView.contentSize才能生效。见https://developer.apple.com/library/content/documentation/WindowsViews/Conceptual/UIScrollView_pg/CreatingBasicScrollViews/CreatingBasicScrollViews.html

Answer 2

这里制作Scroll View的简单演示。

注意：不对图像视图赋予任何约束

下面的scrollview代码：

import UIKit

class ViewController: UIViewController,UIScrollViewDelegate {

    var imgDemo: UIImageView = {
        let img = UIImageView()
        img.contentMode = .scaleAspectFill
        img.isUserInteractionEnabled = true
        return img
    }()


    var scrollView:UIScrollView = {
        let scroll = UIScrollView()
        scroll.maximumZoomScale = 4.0
        scroll.minimumZoomScale = 0.25
        scroll.clipsToBounds = true
        return scroll
    }()

    override func viewDidLoad() {
        super.viewDidLoad()
        imgDemo.frame = CGRect(x: 0, y: 0, width: view.frame.size.width, height: view.frame.size.height)
        imgDemo.image = UIImage(named: "5.jpg")
        scrollView.delegate = self
        scrollView.frame = imgDemo.frame
        scrollView.addSubview(imgDemo)
        view.addSubview(scrollView)
    }

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

}

Swift3 Zoom如何在捏合时更改UICollectionView框架大小？

2 个答案: