swift图片浏览器
思路为一个scrollView上加3个scrollView进行重用，可接收url和本地图片，支持滑动浏览和缩放浏览，长按可保存原图到本地，单击退出，其他都没问题，有个bug“缩放一张后其他图片无法缩放”，待解决
-----更新-----
在写这篇文章的时候又试了一下，竟然把bug解决了，哈哈，我把图片缩放尺寸变成20倍，发现能多缩放几次后才不能缩放，于是就在每次缩放后用setZoomScale(1, animated: false)，问题解决。因为scrollView进行了重用，更新图片后zoomScale没更新，缩放后zoomScale进行累加达到预设值后就不能再放大了。
一共两个文件 代码如下
import UIKit
class photoViewViewController: UIViewController , UIScrollViewDelegate {
//接收图片数组，数组类型可以是url数组，image数组
var isUrl = false
var imgArr = NSMutableArray()
//显示scrollView
var scrollView = UIScrollView()
//显示下标
var sliderLabel = UILabel()
//接收当前图片的序号,默认的是0
var currentIndex : NSInteger = 0
var _subViewList=NSMutableArray()
//三张加载图片
var imageMiddle:UIImage?
var imageLeft:UIImage?
var imageRight:UIImage?
//三个scrollView
var scrollViewLeft = SubScrollView(frame: CGRectMake(0, 0, UIScreen.mainScreen().bounds.size.width, UIScreen.mainScreen().bounds.size.height))
var scrollViewMiddle = SubScrollView(frame: CGRectMake(UIScreen.mainScreen().bounds.width, 0 , UIScreen.mainScreen().bounds.size.width, UIScreen.mainScreen().bounds.size.height))
var scrollViewRight = SubScrollView(frame: CGRectMake(UIScreen.mainScreen().bounds.width*2, 0, UIScreen.mainScreen().bounds.size.width, UIScreen.mainScreen().bounds.size.height))
//图片保存次数限制判断
var isSave = false
override init(nibName nibNameOrNil: String?, bundle nibBundleOrNil: NSBundle?) {
super.init(nibName: nibNameOrNil, bundle: nibBundleOrNil)
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func viewDidLoad() {
super.viewDidLoad()
self.view.backgroundColor = UIColor.blackColor()
self.initScrollView()
self.addLabels()
self.loadPhoto(currentIndex)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
//初始化大scrollView
func initScrollView(){
self.scrollView = UIScrollView.init(frame: CGRectMake(0, 0, UIScreen.mainScreen().bounds.size.width, UIScreen.mainScreen().bounds.size.height))
self.scrollView.pagingEnabled = true
self.scrollView.userInteractionEnabled = true
self.scrollView.showsHorizontalScrollIndicator = false
self.scrollView.delegate = self
self.scrollView.contentSize = CGSizeMake(3 * (UIScreen.mainScreen().bounds.size.width), UIScreen.mainScreen().bounds.size.height)
self.scrollView.contentOffset = CGPointMake(UIScreen.mainScreen().bounds.size.width, 0)
self.view.addSubview(self.scrollView)
let singleTap = UITapGestureRecognizer.init(target: self, action:Selector("handleSingleTap"))
singleTap.numberOfTapsRequired = 1
singleTap.numberOfTouchesRequired = 1
self.scrollView.addGestureRecognizer(singleTap)
let longPressSave = UILongPressGestureRecognizer(target: self, action:"saveImageJudge")
scrollViewMiddle.addGestureRecognizer(longPressSave)
self.scrollView.addSubview(scrollViewLeft)
self.scrollView.addSubview(scrollViewRight)
self.scrollView.addSubview(scrollViewMiddle)
for (var i = 0;i < self.imgArr.count ; i++){
_subViewList.addObject(NSNull)
}
}
//三个scrollView分别加载图片
func loadPhoto(index:NSInteger){
if index<0 || index>=self.imgArr.count{
return
}
//判断图片来源
if isUrl == true{
imageMiddle = UIImage(data: NSData(contentsOfURL: NSURL(string: imgArr[index] as! String)!)!)
if index == 0{
imageLeft = UIImage(data: NSData(contentsOfURL: NSURL(string: imgArr[imgArr.count-1] as! String)!)!)
imageRight = UIImage(data: NSData(contentsOfURL: NSURL(string: imgArr[index+1] as! String)!)!)
}else if index == imgArr.count-1{
imageLeft = UIImage(data: NSData(contentsOfURL: NSURL(string: imgArr[index-1] as! String)!)!)
imageRight = UIImage(data: NSData(contentsOfURL: NSURL(string: imgArr[0] as! String)!)!)
}else{
imageLeft = UIImage(data: NSData(contentsOfURL: NSURL(string: imgArr[index-1] as! String)!)!)
imageRight = UIImage(data: NSData(contentsOfURL: NSURL(string: imgArr[index+1] as! String)!)!)
}
}else{
imageMiddle = imgArr[index] as? UIImage
if index == 0{
imageLeft = imgArr[imgArr.count-1] as? UIImage
imageRight = imgArr[index+1] as? UIImage
}else if index == imgArr.count-1 {
imageLeft = imgArr[index-1] as? UIImage
imageRight = imgArr[0] as? UIImage
}else{
imageLeft = imgArr[index-1] as? UIImage
imageRight = imgArr[index+1] as? UIImage
}
}
scrollViewLeft.imageView.frame = CGRectMake(0, 0 , UIScreen.mainScreen().bounds.width ,UIScreen.mainScreen().bounds.width / imageLeft!.size.width*imageLeft!.size.height)
scrollViewMiddle.imageView.frame = CGRectMake(0, 0 , UIScreen.mainScreen().bounds.width ,UIScreen.mainScreen().bounds.width / imageMiddle!.size.width*imageMiddle!.size.height)
scrollViewRight.imageView.frame = CGRectMake(0, 0 , UIScreen.mainScreen().bounds.width ,UIScreen.mainScreen().bounds.width / imageRight!.size.width*imageRight!.size.height)
scrollViewLeft.imageView.image = imageLeft
scrollViewLeft.imageView.contentMode = UIViewContentMode.ScaleAspectFill
scrollViewLeft.imageView.center.y = UIScreen.mainScreen().bounds.height/2
scrollViewMiddle.imageView.contentMode = UIViewContentMode.ScaleAspectFill
scrollViewMiddle.imageView.image = imageMiddle
scrollViewMiddle.imageView.center.y = UIScreen.mainScreen().bounds.height/2
scrollViewRight.imageView.contentMode = UIViewContentMode.ScaleAspectFill
scrollViewRight.imageView.image = imageRight
scrollViewRight.imageView.center.y = UIScreen.mainScreen().bounds.height/2
//图片宽度都是固定的，若长度大于屏幕长度，要允许上下滑动查看
if scrollViewLeft.imageView.bounds.height > UIScreen.mainScreen().bounds.height{
scrollViewLeft.imageView.frame = CGRectMake(0, 0 , UIScreen.mainScreen().bounds.width ,UIScreen.mainScreen().bounds.width / imageLeft!.size.width*imageLeft!.size.height)
scrollViewLeft.contentSize = CGSizeMake(scrollViewLeft.imageView.frame.width , scrollViewLeft.imageView.frame.height+1)
}else{
scrollViewLeft.contentSize = CGSizeMake(scrollViewLeft.imageView.frame.width , scrollViewLeft.imageView.frame.height)
}
if scrollViewMiddle.imageView.bounds.height > UIScreen.mainScreen().bounds.height{
scrollViewMiddle.imageView.frame = CGRectMake(0, 0 , UIScreen.mainScreen().bounds.width ,UIScreen.mainScreen().bounds.width / imageMiddle!.size.width*imageMiddle!.size.height)
scrollViewMiddle.contentSize = CGSizeMake(scrollViewMiddle.imageView.frame.width , scrollViewMiddle.imageView.frame.height+1)
}else{
scrollViewMiddle.contentSize = CGSizeMake(scrollViewMiddle.imageView.frame.width , scrollViewMiddle.imageView.frame.height)
}
if scrollViewRight.imageView.bounds.height > UIScreen.mainScreen().bounds.height{
scrollViewRight.imageView.frame = CGRectMake(0, 0 , UIScreen.mainScreen().bounds.width ,UIScreen.mainScreen().bounds.width / imageRight!.size.width*imageRight!.size.height)
scrollViewRight.contentSize = CGSizeMake(scrollViewRight.imageView.frame.width , scrollViewRight.imageView.frame.height+1)
}else{
scrollViewRight.contentSize = CGSizeMake(scrollViewRight.imageView.frame.width , scrollViewRight.imageView.frame.height)
}
}
//截图次数限制，不然长按会自动保存两次，bug来源不明
func saveImageJudge(){
if isSave == false{
self.saveImage()
isSave = true
}else {
isSave = false
}
}
//保存图片
func saveImage(){
UIImageWriteToSavedPhotosAlbum(scrollViewMiddle.imageView.image!, self, "image:didFinishSavingWithError:contextInfo:", nil)
}
func image(image: UIImage, didFinishSavingWithError error: NSError?,contextInfo:UnsafePointer<Void>){
if let ee = error{
print(ee)
}else{
let alertVC = UIAlertController(title: "", message: "保存成功！", preferredStyle: .Alert)
let actionItem = UIAlertAction(title: "确定", style: .Default, handler: nil)
alertVC.addAction(actionItem)
self.presentViewController(alertVC, animated: true, completion: nil)
}
}
//单击后退出当前视图
func handleSingleTap(){
self.dismissViewControllerAnimated(true, completion: nil)
}
//添加计数标签
func addLabels(){
self.sliderLabel = UILabel.init(frame: CGRectMake(40, UIScreen.mainScreen().bounds.size.height-64-49, 60, 30))
self.sliderLabel.backgroundColor = UIColor.clearColor()
self.sliderLabel.textColor = UIColor.whiteColor()
self.sliderLabel.text = NSString(format: "%ld/%lu", currentIndex+1,self.imgArr.count) as String
self.view.addSubview(self.sliderLabel)
}
//向右滑动时重新加载图片
func reloadPhotoLeft(index:NSInteger){
if index == imgArr.count-1{
return
}else{
loadPhoto(index+1)
currentIndex+=1
}
}
//向左滑动时重新加载图片
func reloadPhotoRight(index:NSInteger){
if index == 0{
return
}else{
loadPhoto(index-1)
currentIndex-=1
}
}
//结束滑动并滑动超过一半时自动更新图片和标签 setZoomScale必须要重新设置为1，不然会有图片无法缩放的bug. 因为scrollView重用,scale会累加，到达预设值后不能再继续放大
func scrollViewDidEndDecelerating(scrollView: UIScrollView) {
if scrollView.contentOffset.x > UIScreen.mainScreen().bounds.width*1.5{
self.scrollViewLeft.setZoomScale(1, animated: false)
self.scrollViewMiddle.setZoomScale(1, animated: false)
self.scrollViewRight.setZoomScale(1, animated: false)
reloadPhotoLeft(currentIndex)
scrollView.contentOffset.x = UIScreen.mainScreen().bounds.width
self.sliderLabel.text = NSString(format: "%ld/%lu", currentIndex+1,self.imgArr.count) as String
}
if scrollView.contentOffset.x < UIScreen.mainScreen().bounds.width*0.5{
self.scrollViewLeft.setZoomScale(1, animated: false)
self.scrollViewMiddle.setZoomScale(1, animated: false)
self.scrollViewRight.setZoomScale(1, animated: false)
reloadPhotoRight(currentIndex)
scrollView.contentOffset.x = UIScreen.mainScreen().bounds.width
self.sliderLabel.text = NSString(format: "%ld/%lu", currentIndex+1,self.imgArr.count) as String
}
}
//防止循环轮播
func scrollViewDidScroll(scrollView: UIScrollView) {
if currentIndex == (imgArr.count-1){
if self.scrollView.contentOffset.x >= (UIScreen.mainScreen().bounds.width+1){
self.scrollView.contentOffset.x = UIScreen.mainScreen().bounds.width
self.scrollView.scrollEnabled = false
}
}
if currentIndex == 0{
if self.scrollView.contentOffset.x <= UIScreen.mainScreen().bounds.width-1{
self.scrollView.contentOffset.x = UIScreen.mainScreen().bounds.width
self.scrollView.scrollEnabled = false
}
}
}
//拖动结束后允许继续拖动
func scrollViewDidEndDragging(scrollView: UIScrollView, willDecelerate decelerate: Bool) {
self.scrollView.scrollEnabled = true
}
}
import UIKit
class SubScrollView: UIScrollView,UIScrollViewDelegate {
var imageView = UIImageView()
override init(frame: CGRect) {
super.init(frame:frame)
self.delegate = self
self.minimumZoomScale = 1
self.maximumZoomScale = 2
self.showsHorizontalScrollIndicator = false
self.showsVerticalScrollIndicator = false
self.userInteractionEnabled = true
self.bounces = false
self.scrollEnabled = true
self.addSubview(imageView)
self.setZoomScale(1, animated: true)
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
func viewForZoomingInScrollView(scrollView: UIScrollView) -> UIView? {
return self.imageView
}
func scrollViewDidZoom(scrollView: UIScrollView) {
//根据不同图片长宽的情况设置contentsize
if self.imageView.bounds.height > UIScreen.mainScreen().bounds.height{
self.imageView.frame = CGRectMake(0, 0 , self.imageView.frame.width ,self.imageView.frame.height)
self.contentSize = CGSizeMake(self.imageView.frame.width , self.imageView.frame.height+1)
}else if self.imageView.bounds.height*2 < UIScreen.mainScreen().bounds.height{
self.imageView.frame = CGRectMake(0, (UIScreen.mainScreen().bounds.height - self.imageView.frame.height)/2,self.imageView.frame.width ,self.imageView.frame.height)
self.contentSize = CGSizeMake(self.imageView.frame.width , self.imageView.frame.height+1)
}
else{
self.imageView.frame = CGRectMake(0, 0 , self.imageView.frame.width ,self.imageView.frame.height)
self.contentSize = CGSizeMake(self.imageView.frame.width , self.imageView.frame.height+1)
}
}
func scrollViewDidEndZooming(scrollView: UIScrollView, withView view: UIView?, atScale scale: CGFloat) {
//长度小于屏幕宽度的图片放大缩小后回归中心
if self.imageView.frame.height <= UIScreen.mainScreen().bounds.height && self.zoomScale == 1{
self.imageView.center.y = self.center.y
}
}
}
