swift - 如何在多个页面中快速缩放图像

Posted 2023-02-23

【中文标题】swift - 如何在多个页面中快速缩放图像

【英文标题】：How to zoom images when they are in multiple pages in swift

【发布时间】：2016-07-30 05:07:10

【问题描述】：

我有一个主滚动视图，在该主滚动视图中我有一个具有 UIImageView 的子滚动视图。我在正确缩放滚动视图时遇到问题。每当我尝试放大图像时，视图只是四处移动，但图像没有放大。我不知道我做错了什么？有人可以帮我看看有什么问题吗？这是我的代码：

import UIKit

class ImageViewerViewController: UIViewController, UIScrollViewDelegate 

    @IBOutlet weak var scrollView: UIScrollView!

    @IBOutlet weak var pageControl: UIPageControl!

    var tap: UITapGestureRecognizer?

    var seguedAlbumImagePathArray=[]
    var seguedCurrentImageIndex: Int?

    var imageView: UIView?
    var childScrollView: UIScrollView?
    var imagev: UIImageView?

    var totalPages: Int = 0

    override func shouldAutorotate() -> Bool 
        return false
    

    override func supportedInterfaceOrientations() -> UIInterfaceOrientationMask 
        return UIInterfaceOrientationMask.Portrait
    

    override func viewDidLoad() 
        super.viewDidLoad()
        totalPages = seguedAlbumImagePathArray.count
        view.bringSubviewToFront(pageControl)

        tap = UITapGestureRecognizer(target: self, action: #selector(ImageViewerViewController.dismissImageViewer))
        scrollView.addGestureRecognizer(tap!)
    

    func dismissImageViewer() 
        UIView.animateWithDuration(0.2, animations: () -> Void in
            self.scrollView.alpha=0
        )
        NSTimer.scheduledTimerWithTimeInterval(0.13, target: self, selector: #selector(self.dismissView), userInfo: nil, repeats: true)
    

    func dismissView() 
        self.presentingViewController?.dismissViewControllerAnimated(false, completion: 
            let secondPresentingVC = self.presentingViewController?.presentingViewController;
            secondPresentingVC?.dismissViewControllerAnimated(false, completion: )
        )
    

    override func viewDidAppear(animated: Bool) 
        super.viewDidAppear(animated)

        configureScrollView()
        configurePageControl()
    


    override func didReceiveMemoryWarning() 
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    


    override func preferredStatusBarStyle() -> UIStatusBarStyle 
        return UIStatusBarStyle.LightContent
    


    // MARK: Custom method implementation

    func configureScrollView() 

        self.scrollView.backgroundColor = UIColor.blackColor()

        // Enable paging.
        scrollView.pagingEnabled = true

        // Set the following flag values.
        scrollView.showsHorizontalScrollIndicator = false
        scrollView.showsVerticalScrollIndicator = false
        scrollView.scrollsToTop = false

        // Set the scrollview content size.
        scrollView.contentSize = CGSizeMake(scrollView.frame.size.width * CGFloat(totalPages), scrollView.frame.size.height)

        // Set self as the delegate of the scrollview.
        scrollView.delegate = self

        // Load the ImageView view from the ImageView.xib file and configure it properly.
        for i in 0 ..< totalPages 
            // Load the ImageView view.
            imageView = NSBundle.mainBundle().loadNibNamed("ImageView", owner: self, options: nil)[0] as! UIView

            imageView!.backgroundColor = UIColor.blackColor()
            // Set its frame and the background color.
            imageView!.frame = CGRectMake(CGFloat(i) * scrollView.frame.size.width, scrollView.frame.origin.y, scrollView.frame.size.width, scrollView.frame.size.height)
            //imageView.backgroundColor = sampleBGColors[i]

            // Set the proper message to the test view's label.
            let label = imageView!.viewWithTag(1) as! UILabel
            label.text = "\(i + 1)/\(totalPages)"

            childScrollView = imageView!.viewWithTag(2) as? UIScrollView
            childScrollView?.minimumZoomScale=1.0
            childScrollView?.maximumZoomScale=6.0
            childScrollView?.delegate = self

            imagev = childScrollView!.viewWithTag(3) as? UIImageView
            view.sendSubviewToBack(imagev!)

            if let imageData = NSUserDefaults.standardUserDefaults().objectForKey(seguedAlbumImagePathArray[i] as! String),
                let imageToDisplay = UIImage(data: imageData as! NSData) 
                imagev!.image = imageToDisplay
            
            else 
                ImageLoader.sharedLoader.imageForUrl(seguedAlbumImagePathArray[i] as! String, completionHandler:(image: UIImage?, url: String) in
                    self.imagev!.image = image
                )
            

            var frame: CGRect = scrollView.frame
            frame.origin.x = frame.size.width * CGFloat(seguedCurrentImageIndex!)
            frame.origin.y = 0
            scrollView.scrollRectToVisible(frame, animated: false)

            scrollView.addSubview(imageView!)
            //scrollView.setContentOffset(CGPoint, animated: true)
            print(scrollView.contentOffset)
        
    


    func configurePageControl() 
        // Set the total pages to the page control.
        pageControl.numberOfPages = totalPages

        // Set the initial page.
        pageControl.currentPage = seguedCurrentImageIndex!
    


    // MARK: UIScrollViewDelegate method implementation

    func scrollViewDidScroll(scrollView: UIScrollView) 
        // Calculate the new page index depending on the content offset.
        let currentPage = floor(scrollView.contentOffset.x / UIScreen.mainScreen().bounds.size.width);
        //1.025 = 328/320
        // Set the new page index to the page control.
        pageControl.currentPage = Int(currentPage)
    


    // MARK: IBAction method implementation

    @IBAction func changePage(sender: AnyObject) 
        // Calculate the frame that should scroll to based on the page control current page.
        var newFrame = scrollView.frame
        newFrame.origin.x = newFrame.size.width * CGFloat(pageControl.currentPage)
        scrollView.scrollRectToVisible(newFrame, animated: true)

    

    func viewForZoomingInScrollView(scrollView: UIScrollView) -> UIView? 
        return self.imagev
    

【参考方案1】：

当我将滚动视图放在 UIcontrolViewCONtroller 下时，我遇到了类似的问题。 删除这个 -

func viewForZoomingInScrollView(scrollView: UIScrollView) -> UIView? 
        return self.imagev
    

并使用

  func viewForZooming( in scrollView: UIScrollView) -> UIView? 
        return imgview
    

这对我有用。