iOS中UIScrollView嵌套UIImageView实现图片滑动浏览、缩放

来源：互联网发布：php空间服务器编辑：程序博客网时间：2024/05/16 12:10
一开始的时候是UIScrollView直接嵌套UIImageView，滑动浏览都是正常的，但是不能伸缩，试了UIScrollVIew自身的zoom方法，也试用了pinch gesture的方法都无果，后来想到了用UIScrollView嵌套UIScrollVIew再嵌套UIImageView的方法实现，然后缩放用的是UIScrollView自身的缩放方法，成功，很棒。
载入图片是用的SDWebImage，提示框用的是MBProgressHUD
实现了在当前图片放大情况下，滑动到相邻的图片时对当前图片恢复到原始比例。以及缩小时保证图片在正中间。解决了滑动时显示多个“载入中”的BUG
以下是源码：（直接复制不能运行）
    func showImages(theView:UIView,imageNamesTMP:[String])    {        println("showImages")        imageNames = imageNamesTMP                        var numberOfImages:CGFloat = (CGFloat)(imageNames.count)                                imageBigScrollView.contentSize = CGSizeMake(SCREENWIDTH * numberOfImages, SCREENHEIGHT)                imageSmallScrollViews = NSMutableArray()        for(var i = 0; i < (Int)(numberOfImages);i++)        {            var smallScrollView = UIScrollView(frame: CGRectMake(SCREENWIDTH * (CGFloat)(i), 0, SCREENWIDTH, SCREENHEIGHT))            smallScrollView.pagingEnabled = false            smallScrollView.contentSize = CGSizeMake(SCREENWIDTH, SCREENHEIGHT)            smallScrollView.delegate = self            smallScrollView.showsHorizontalScrollIndicator = false            smallScrollView.showsVerticalScrollIndicator = false            smallScrollView.minimumZoomScale = 0.2            smallScrollView.maximumZoomScale = 8                        imageBigScrollView.addSubview(smallScrollView)            imageSmallScrollViews.addObject(smallScrollView)        }                        var pageControlHeight:CGFloat = 20        imagePageControl = UIPageControl(frame: CGRectMake(0, SCREENHEIGHT - pageControlHeight, SCREENWIDTH, pageControlHeight))        theView.addSubview(imagePageControl)        var longGesture = UILongPressGestureRecognizer(target: self, action: "longPressed:")        imageBigScrollView.addGestureRecognizer(longGesture)                        imagePageControl.numberOfPages = (Int)(numberOfImages)        imagePageControl.currentPage = 0        imagePageControl.backgroundColor = UIColor.clearColor()        imagePageControl.hidesForSinglePage = true        imagePageControl.defersCurrentPageDisplay = true        needToZoomIndex = imagePageControl.currentPage                imageViews = NSMutableArray()        imageFlag = NSMutableArray()                for(var i = 0; i < imageNames.count; i++)        {            imageViews.addObject(UIImageView())            imageFlag.addObject(0)        }        loadImageWithPage(0)        loadImageWithPage(1)    }    func loadImageWithPage(page:Int)    {        if(page < 0 || page >= imageNames.count)        {            return        }                var flag = imageFlag.objectAtIndex(page) as Int        var iView:UIImageView = imageViews.objectAtIndex(page) as UIImageView                if(flag == 0)        {                        var frame = self.imageBigScrollView.frame            frame.origin.x = 0            frame.origin.y = 0                        iView.userInteractionEnabled = true            iView.frame = frame            iView.contentMode = UIViewContentMode.ScaleAspectFit            (self.imageSmallScrollViews.objectAtIndex(page) as UIScrollView).addSubview(iView)            println("add one image:\(page)")            var hud:SMS_MBProgressHUD = SMS_MBProgressHUD.showMessagManually("载入中", toView: iView)            self.imageFlag.replaceObjectAtIndex(page, withObject: 1)                        iView.sd_setImageWithPreviousCachedImageWithURL(NSURL(string: imageNames[page]), andPlaceholderImage: nil, options: SDWebImageOptions.ProgressiveDownload, progress: { (a, b) -> Void in//                println("\(page): \(b)")//                hud.progress = (Float)(a)/(Float)(b)                                            }, completed: { (tmpImage, err, cachType, url) -> Void in                hud.hide(true)                println("pic \(page) load complete")                if let error = err                {                                    }                else                {                    self.imageFlag.replaceObjectAtIndex(page, withObject: 1)                    self.imageViews.replaceObjectAtIndex(page, withObject: iView)                                        //                    iView.image.set                                                                                                    //                CGRectMake(frame.size.width * (CGFloat)(page), (SCREENHEIGHT - image.size.height * SCREENWIDTH / image.size.width)/2, SCREENWIDTH, image.size.height * SCREENWIDTH / image.size.width)//                    println(frame.width)                                    }                            })                    }                    }    func scrollViewDidScroll(scrollView: UIScrollView) {        if(pageControlUsed == true)        {            return        }                var pageWidth = imageBigScrollView.frame.size.width        var page:Int = (Int)(floor((imageBigScrollView.contentOffset.x - pageWidth / 2) / pageWidth) + 1)        imagePageControl.currentPage = page                self.loadImageWithPage(page - 1)        self.loadImageWithPage(page)        self.loadImageWithPage(page + 1)                if(page != lastPageIndex)        {            setZoomToOne(lastPageIndex)            lastPageIndex = page        }    }        func scrollViewWillBeginDragging(scrollView: UIScrollView) {        pageControlUsed = false    }    func scrollViewDidEndDecelerating(scrollView: UIScrollView) {        pageControlUsed = false    }        func setZoomToOne(page:Int)    {                if(page < 0 || page >= imageNames.count || lastSetIndex == page)        {            return        }        println("set:\(page) \(lastPageIndex)")        lastSetIndex = page                needToZoomIndex = page        (imageSmallScrollViews.objectAtIndex(page) as UIScrollView).setZoomScale(1, animated: true)        needToZoomIndex = imagePageControl.currentPage    }        func tapPressed(sender:UITapGestureRecognizer)    {        self.dismissViewControllerAnimated(true, completion: nil)    }    func longPressed(sender:UILongPressGestureRecognizer)    {                println("\(imagePageControl.currentPage)")        if(imagePageControl.currentPage != lastLongPressIndex)        {            lastLongPressIndex = imagePageControl.currentPage            UIActionSheet(title: "选择" , delegate: self, cancelButtonTitle: nil, destructiveButtonTitle: nil, otherButtonTitles: "保存图片","取消").showInView(self.view)        }        else        {            lastLongPressIndex = -1        }    }    func pinchPressed(sender:UIPinchGestureRecognizer)    {        println("pinch")        var iView:UIImageView = imageViews.objectAtIndex(imagePageControl.currentPage) as UIImageView        if(sender.state == UIGestureRecognizerState.Began)        {            beganScale = (imageSmallScrollViews.objectAtIndex(imagePageControl.currentPage) as UIScrollView).zoomScale        }        (imageSmallScrollViews.objectAtIndex(imagePageControl.currentPage) as UIScrollView).setZoomScale(beganScale * sender.scale, animated: true)                        if(sender.state == UIGestureRecognizerState.Ended)        {                        scrollViewEnd()        }            }    func scrollViewEnd()    {//        println("end")        var isv = imageSmallScrollViews.objectAtIndex(imagePageControl.currentPage) as UIScrollView        if(isv.zoomScale < 1.0)        {            println("set back 1")            isv.setZoomScale(1, animated: true)        }        else if(isv.zoomScale > 2.0)        {            isv.setZoomScale(2.0, animated: true)        }                    }        func viewForZoomingInScrollView(scrollView: UIScrollView) -> UIView? {//        println("view for zoom")        return imageViews.objectAtIndex(needToZoomIndex) as UIImageView    }    func scrollViewDidZoom(scrollView: UIScrollView) {        var iView:UIImageView = imageViews.objectAtIndex(imagePageControl.currentPage) as UIImageView        var isv = imageSmallScrollViews.objectAtIndex(imagePageControl.currentPage) as UIScrollView        if(isv.zoomScale < 1.0)        {            isv.contentOffset = CGPointMake(-(isv.frame.width - iView.frame.size.width) / 2, -(isv.frame.height - iView.frame.size.height) / 2)                    }    }    func scrollViewDidEndZooming(scrollView: UIScrollView, withView view: UIView!, atScale scale: CGFloat) {        scrollViewEnd()    }        func actionSheet(actionSheet: UIActionSheet, clickedButtonAtIndex buttonIndex: Int) {        println("actionsheet:\(buttonIndex)")        if(buttonIndex == 0)        {            UIImageWriteToSavedPhotosAlbum((imageViews.objectAtIndex(imagePageControl.currentPage) as UIImageView).image, self, "imageSavedToPhotosAlbum:didFinishSavingWithError:contextInfo:", nil)        }    }    func imageSavedToPhotosAlbum(image:UIImage, didFinishSavingWithError error:NSError?, contextInfo:AnyObject)    {        if let err = error        {            SMS_MBProgressHUD.showError("保存失败", toView: self.view)        }        else        {            SMS_MBProgressHUD.showCompleteMessage("保存成功", toView: self.view)        }    }        override func didReceiveMemoryWarning() {        super.didReceiveMemoryWarning()        // Dispose of any resources that can be recreated.    }
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