swift基础学习(九)

####1. 所用到的知识点

• scrollview代理方法
• 手势

####2.效果图

####3.代码

• 自定义页面的代码

import UIKit

class  JdryZoomView: UIControl, UIScrollViewDelegate {

fileprivate let screenWidth: CGFloat = UIScreen.main.bounds.width
fileprivate let screenHeight: CGFloat = UIScreen.main.bounds.height
fileprivate let maxScale: CGFloat = 3.0 // 最大比例
fileprivate let minScale: CGFloat = 1.0 // 最小比例
fileprivate let animDuration: TimeInterval = 0.2 //动画时间

open var originFrame: CGRect = CGRect.zero
open var image: UIImage? {
didSet {
if let _image = image{
if self.originFrame == CGRect.zero {
let imageViewH = _image.size.height / (image?.size.width)! * screenWidth
self.imageView?.bounds = CGRect(x: 0, y: 0, width: screenWidth, height: imageViewH)
self.imageView?.center = (scrollView?.center)!
} else {
self.imageView?.frame = self.originFrame
}
self.imageView?.image = image
}
}
}

fileprivate var scrollView: UIScrollView?
fileprivate var imageView: UIImageView?

fileprivate var scale: CGFloat = 1.0 // 当前缩放比例
fileprivate var touchX: CGFloat = 0.0 //双击点的X坐标
fileprivate var touchY: CGFloat = 0.0 //双击点Y的坐标
fileprivate var isDoubleTaping: Bool = false // 是否双击

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

}

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

fileprivate func initAllView() {
self.alpha = 0.0
self.scrollView = UIScrollView()
self.scrollView?.showsVerticalScrollIndicator = false
self.scrollView?.showsHorizontalScrollIndicator = false
self.scrollView?.maximumZoomScale = maxScale
self.scrollView?.minimumZoomScale = minScale
self.scrollView?.delegate = self
self.scrollView?.backgroundColor = UIColor.black
self.scrollView?.frame = self.bounds
self.addSubview(self.scrollView!)

//        添加手势
//        1.点击手势
let  singleTap = UITapGestureRecognizer(target: self, action: #selector(singleTapClick(_:)))
singleTap.numberOfTapsRequired = 1
self.scrollView?.addGestureRecognizer(singleTap)

//        2.双击手势
let doubleTap = UITapGestureRecognizer(target: self, action: #selector(doubleTapClick(tap:)))
doubleTap.numberOfTapsRequired = 2
self.scrollView?.addGestureRecognizer(doubleTap)
singleTap.require(toFail: doubleTap)

//        初始化 UIImageView
self.imageView = UIImageView()
self.scrollView?.addSubview(self.imageView!)
}

open func show() {
self.scrollView?.backgroundColor = UIColor.black
UIView.animate(withDuration: self.animDuration, delay: 0, options: UIViewAnimationOptions.allowUserInteraction, animations: {
self.imageView?.bounds = CGRect(x: 0, y: 0, width: self.screenWidth, height: (self.image?.size.height)! / (self.image?.size.width)! * self.screenWidth)
self.alpha = 1.0
}) { (finished) in
}
}

//    单击手势
func singleTapClick(_ tap: UITapGestureRecognizer) {
self.scrollView?.setZoomScale(self.minScale, animated: false)
UIView.animate(withDuration: self.animDuration, delay: 0, options: .allowUserInteraction, animations: {
self.imageView?.frame = self.originFrame
self.scrollView?.backgroundColor = UIColor.clear
UIApplication.shared.keyWindow?.windowLevel = UIWindowLevelNormal

}) { (finished) in

self.alpha = 0
self.scrollView?.backgroundColor = UIColor.black
self.originFrame = CGRect.zero
self.scale = self.minScale
self.removeFromSuperview()

}
}

//    双击手势
func doubleTapClick(tap: UITapGestureRecognizer) {
self.touchX = tap.location(in: tap.view).x
self.touchY = tap.location(in: tap.view).y

if self.scale > 1.0 {
self.scale = 1.0
self.scrollView?.setZoomScale(self.scale, animated: true)
} else {
self.scale = maxScale
self.isDoubleTaping = true
self.scrollView?.setZoomScale(maxScale, animated: true)
}
self.isDoubleTaping = false
}

//    scrollview 代理
func scrollViewDidEndZooming(_ scrollView: UIScrollView, with view: UIView?, atScale scale: CGFloat) {
self.scale = scale
}

func viewForZooming(in scrollView: UIScrollView) -> UIView? {
return self.imageView!
}

open func scrollViewDidZoom(_ scrollView: UIScrollView) {
//当捏或移动时，需要对center重新定义以达到正确显示位置
var centerX = scrollView.center.x
var centerY = scrollView.center.y
centerX = scrollView.contentSize.width > scrollView.frame.size.width ? scrollView.contentSize.width / 2 : centerX
centerY = scrollView.contentSize.height > scrollView.frame.size.height ?scrollView.contentSize.height / 2 : centerY

self.imageView?.center = CGPoint(x: centerX, y: centerY)

// ****************双击放大图片关键代码*******************

if isDoubleTaping {
let contentOffset = self.scrollView?.contentOffset
let center = self.center
let offsetX = center.x - self.touchX
//            let offsetY = center.y - self.touchY
self.scrollView?.contentOffset = CGPoint(x: (contentOffset?.x)! - offsetX * 2.2, y: (contentOffset?.y)!)
}

// ****************************************************

}

deinit {
print("释放")
}
}

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• 主控制器的代码

import UIKit

class ViewController: UIViewController, UIScrollViewDelegate {

fileprivate let screenWidth: CGFloat = UIScreen.main.bounds.width
fileprivate let scrollHeight: CGFloat = UIScreen.main.bounds.height


@IBOutlet weak var imageView: UIImageView!

var zoomView: JdryZoomView?


override func viewDidLoad() {
super.viewDidLoad()
self.imageView.isUserInteractionEnabled = true
self.imageView.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(tapClick(_:))))
}

func tapClick(_ tap: UITapGestureRecognizer) {
if zoomView == nil {
let frame = UIScreen.main.bounds
zoomView = JdryZoomView(frame: frame)

}

if zoomView?.superview == nil {
UIApplication.shared.keyWindow?.windowLevel = UIWindowLevelStatusBar
UIApplication.shared.keyWindow?.addSubview(zoomView!)
}

let  imageviewFram = self.view.convert(self.imageView.frame, to: UIApplication.shared.keyWindow)
zoomView?.originFrame = imageviewFram
zoomView?.image = self.imageView.image
zoomView?.show()
}

}

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