效果图
效果图
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1、布局
结构如下
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2、然后设置ScrollView
scrollView.addSubview(imageView)
scrollView.autoresizingMask = [.FlexibleWidth, .FlexibleHeight]
scrollView.zoomScale = scrollView.minimumZoomScale
scrollView.delegate = self
setZoomScaleFor(scrollView.frame.size)
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setZoomScaleFor...方法
private func setZoomScaleFor(srollViewSize: CGSize) {
let imageSize = imageView.bounds.size
let widthScale = srollViewSize.width / imageSize.width
let heightScale = srollViewSize.height / imageSize.height
let minimunScale = min(widthScale, heightScale)
scrollView.minimumZoomScale = minimunScale
scrollView.maximumZoomScale = 3.0
}
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添加三个属性
var top : CGFloat = 0
var imageView : UIImageView = {
let iv = UIImageView(image: UIImage(named: "item"))
iv.sizeToFit()
return iv
}()
var showImageView: UIImageView = {
let iv = UIImageView(image: UIImage(named: "item"))
iv.userInteractionEnabled = true
return iv
}()
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为showImageView添加手势，在ViewDidLoad中
let tap : UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(ViewController.showScrollView))
showImageView.addGestureRecognizer(tap)
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实现手势方法
@objc private func showScrollView(){
UIView.animateWithDuration(0.5, animations: {
self.showImageView.frame = self.scrollView.frame
self.showImageView.frame.size.width = self.scrollView.contentSize.width
}) { (completion) in
self.scrollView.hidden = false
self.showImageView.removeFromSuperview()
self.top = 0
}
}
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实现scrollView的代理方法
func scrollViewDidZoom(scrollView: UIScrollView) {
top = scrollView.contentInset.top
self.recenterImage()
}
func scrollViewDidEndZooming(scrollView: UIScrollView, withView view: UIView?, atScale scale: CGFloat) {
if top >= 1 {
scrollView.hidden = true
showImageView.layoutMargins = scrollView.contentInset
self.view.addSubview(showImageView)
UIView.animateWithDuration(0.5, animations: {
self.showImageView.frame = CGRect(x: 10, y: 20, width: 100, height: 100)
})
}
}
func viewForZoomingInScrollView(scrollView: UIScrollView) -> UIView? {
if top > 1 {
return nil
}
return self.imageView
}
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最后通过recenterImage方法设置图片大小
private func recenterImage() {
let scrollViewSize = scrollView.bounds.size
let imageViewSize = imageView.frame.size
let horizontalSpace = imageViewSize.width < scrollViewSize.width ? (scrollViewSize.width - imageViewSize.width) / 2.0 : 0
let verticalSpace = imageViewSize.height < scrollViewSize.height ? (scrollViewSize.height - imageViewSize.width) / 2.0 :0
scrollView.contentInset = UIEdgeInsetsMake(verticalSpace, horizontalSpace, verticalSpace, horizontalSpace)
}
