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[已解决]swift中实现图片的捏pinch去缩放图片

Swift crifan 1612浏览 0评论

已经用代码:

    override func viewDidLoad() {
        super.viewDidLoad()
       
        self.title = bubbleImageView.resMsg.fileItem.name
       
        self.imageView.autoresizingMask = [.FlexibleWidth, .FlexibleHeight]
        self.imageView.contentMode = .ScaleAspectFit
       
        self.view.addSubview(self.imageView)
       
        constrain(imageView) {imageView in
            //imageView.edges <= imageView.superview!.edges
            imageView.left == imageView.superview!.left
            imageView.top == imageView.superview!.top
            imageView.right == imageView.superview!.right
            imageView.bottom == imageView.superview!.bottom
        }
    }

显示了图片:

现在需要去实现:

pinch,捏,实现缩放图片

swift imageview pinch to scale

UIImageView pinch zoom swift – Stack Overflow

Scale images with Pinch Gesture in iOS with Swift – iOScreator

Swift image zoom · GitHub

Pinch To Zoom – UIImageView with Swift — Vea Software

UIScrollView Tutorial: Getting Started

最后用代码:

//
//  ImageViewController.swift
//  JianDao
//
//  Created by licrifan on 16/3/2.
//  Copyright © 2016 licrifan. All rights reserved.
//
import UIKit
class ImageViewController: UIViewController, UIScrollViewDelegate {
    var bubbleImageView:ImageBubbleView
   
    var imageView: UIImageView
   
    var scrollView:UIScrollView
   
    init(bubbleImageView:ImageBubbleView) {
        self.bubbleImageView = bubbleImageView
//        self.imageView = bubbleImageView.imageView
        self.imageView = UIImageView(image: bubbleImageView.imageView.image!)
       
        self.scrollView = UIScrollView()
       
        super.init(nibName: nil, bundle: nil)
    }
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
   
    override func viewDidLoad() {
        super.viewDidLoad()
       
        self.title = bubbleImageView.resMsg.fileItem.name
       
        self.scrollView.addSubview(self.imageView)
        self.view.addSubview(self.scrollView)
        self.scrollView.frame = CGRectMake(
            0,
            0,
            self.view.frame.width,
            self.view.frame.height
                – statusBarFrame.height //20
                – HeightNaviBar) //44
       
        let imageSize = self.imageView.image!.size
//        print("imageSize=\(imageSize)") //(1359.0, 901.0)
       
        self.scrollView.contentSize = imageSize
        self.scrollView.bounces = false
        self.scrollView.showsHorizontalScrollIndicator = false
        self.scrollView.showsVerticalScrollIndicator = false
        self.scrollView.userInteractionEnabled = true
        self.scrollView.delegate = self
        self.scrollView.bouncesZoom = false
        self.scrollView.scrollsToTop = false
        let scrollViewFrame = scrollView.frame
//        print("scrollViewFrame=\(scrollViewFrame)") //(0.0, 0.0, 375.0, 667.0)
        let scaleWidth = scrollViewFrame.size.width / scrollView.contentSize.width
//        print("scaleWidth=\(scaleWidth)") //0.275938189845475
        let scaleHeight = scrollViewFrame.size.height / scrollView.contentSize.height
//        print("scaleHeight=\(scaleHeight)") //0.740288568257492
        let minScale = min(scaleWidth, scaleHeight)
//        print("minScale=\(minScale)") //0.275938189845475
       
        self.scrollView.minimumZoomScale = minScale
        self.scrollView.maximumZoomScale = 1.0
        self.scrollView.zoomScale = minScale
       
        centerScrollViewContents()
       
        let doubleTap = UITapGestureRecognizer(target: self, action: "doubleTapped:")
        doubleTap.numberOfTapsRequired = 2
        doubleTap.numberOfTouchesRequired = 1
        self.scrollView.addGestureRecognizer(doubleTap)
    }
   
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }
    func centerScrollViewContents() {
        let boundsSize = self.scrollView.bounds.size
//        print("boundsSize=\(boundsSize)")
        var contentsFrame = self.imageView.frame
//        print("contentsFrame=\(contentsFrame)")
       
        if contentsFrame.size.width < boundsSize.width {
            contentsFrame.origin.x = (boundsSize.width – contentsFrame.size.width) / 2.0
        } else {
            contentsFrame.origin.x = 0.0
        }
       
        if contentsFrame.size.height < boundsSize.height {
            contentsFrame.origin.y = (boundsSize.height – contentsFrame.size.height) / 2.0
        } else {
            contentsFrame.origin.y = 0.0
        }
       
//        print("contentsFrame=\(contentsFrame)")
        self.imageView.frame = contentsFrame
    }
   
    func viewForZoomingInScrollView(scrollView: UIScrollView) -> UIView? {
        return self.imageView
    }
   
    func scrollViewDidZoom(scrollView: UIScrollView) {
        centerScrollViewContents()
    }
   
//    func doubleTapped(tapGesture: UITapGestureRecognizer) {
//        print("tapGesture=\(tapGesture)")
//        if (self.scrollView.zoomScale == self.scrollView.minimumZoomScale) {
//            let center = tapGesture.locationInView(self.scrollView)
//            print("center=\(center)")
//            let size = self.imageView.image!.size
//            print("size=\(size)")
//            let zoomRect = CGRectMake(center.x, center.y, (size.width / 2), (size.height / 2))
//            print("zoomRect=\(zoomRect)")
//            self.scrollView.zoomToRect(zoomRect, animated: true)
//        } else {
//            self.scrollView.setZoomScale(self.scrollView.minimumZoomScale, animated: true)
//        }
//    }
   
    func doubleTapped(recognizer: UITapGestureRecognizer) {
        if (self.scrollView.zoomScale == self.scrollView.maximumZoomScale) {
            self.scrollView.setZoomScale(self.scrollView.minimumZoomScale, animated: true)
        } else {
            let pointInView = recognizer.locationInView(self.imageView)
//            print("pointInView=\(pointInView)") //(898.155653734425, 425.882443769075)
           
            var newZoomScale = scrollView.zoomScale * 1.5
//            print("newZoomScale=\(newZoomScale)") //0.986187634979701
           
            newZoomScale = min(newZoomScale, scrollView.maximumZoomScale)
//            print("newZoomScale=\(newZoomScale)") //0.986187634979701
           
            let scrollViewSize = scrollView.bounds.size
//            print("scrollViewSize=\(scrollViewSize)") //(375.0, 603.0)
           
            let w = scrollViewSize.width / newZoomScale
            let h = scrollViewSize.height / newZoomScale
            let x = pointInView.x – (w / 2.0)
            let y = pointInView.y – (h / 2.0)
           
            let rectToZoomTo = CGRectMake(x, y, w, h);
//            print("rectToZoomTo=\(rectToZoomTo)") //(708.029562766088, 120.159689491989, 380.252181936674, 611.445508554172)
           
            scrollView.zoomToRect(rectToZoomTo, animated: true)
        }
    }
}

至少实现了基本的功能了:

显示图片,是图片居中,且已当前屏幕缩放适配:

双击,自动放大1.5倍:

可以拖动:

放到最大后,双击会到最开始适配屏幕:

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