iOS：在滚动视图中添加图像视图以进行缩放

在iOS开发中，滚动视图是一种非常常见的UI控件，用于展示大量内容并支持滚动操作。而在滚动视图中添加图像视图并实现缩放功能是一项常见的需求。本文将介绍如何在iOS应用中实现这一功能，并提供相关的示例代码。

swift
let scrollView = UIScrollView(frame: CGRect(x: 0, y: 0, width: view.frame.width, height: view.frame.height))
scrollView.contentSize = CGSize(width: view.frame.width, height: view.frame.height)
view.addSubview(scrollView)

swift
let imageView = UIImageView(image: UIImage(named: "example_image"))
imageView.contentMode = .scaleAspectFit
scrollView.addSubview(imageView)

swift
class ViewController: UIViewController, UIScrollViewDelegate {
    // ...
    override func viewDidLoad() {
        // ...
        scrollView.delegate = self
        scrollView.minimumZoomScale = 0.5
        scrollView.maximumZoomScale = 2.0
    }
    
    func viewForZooming(in scrollView: UIScrollView) -> UIView? {
        return imageView
    }
}

swift
import UIKit
class ViewController: UIViewController, UIScrollViewDelegate {
    let scrollView = UIScrollView(frame: CGRect(x: 0, y: 0, width: UIScreen.main.bounds.width, height: UIScreen.main.bounds.height))
    let imageView = UIImageView(image: UIImage(named: "example_image"))
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        scrollView.contentSize = CGSize(width: UIScreen.main.bounds.width, height: UIScreen.main.bounds.height)
        scrollView.delegate = self
        scrollView.minimumZoomScale = 0.5
        scrollView.maximumZoomScale = 2.0
        
        imageView.contentMode = .scaleAspectFit
        
        scrollView.addSubview(imageView)
        view.addSubview(scrollView)
    }
    
    func viewForZooming(in scrollView: UIScrollView) -> UIView? {
        return imageView
    }
}