UIScrollView 滾動視圖

• 首先初始化一個UIScrollView冯事，并且設置好它的x膊存，y以及寬和高遥倦，
• 這里我們將他的寬高設置成我們模擬器的大小。

let scr = UIScrollView(frame:CGRect(x: 0, y: 0, width: self.view.frame.size.width, height: self.view.frame.size.height))
//添加背景顏色   
scr.backgroundColor = UIColor.red

• 然后我們設置碉考，滑動區(qū)域的大小塌计，這里我們會添加三張圖片，所以給模擬器的寬*3.高依然是模擬器的高

//設置滑動內(nèi)容區(qū)域的大小
scr .contentSize = CGSize(width: self.view.frame.size.width * 3, height: self.view.frame.size.height)
//添加到父視圖上
self.view.addSubview(scr)

• 下面是一些屬性

//是否可以整頁翻動
scr.isPagingEnabled = true
//觸壁反彈
scr.bounces = false
//取消滑動條
scr.showsHorizontalScrollIndicator = false
scr.indicatorStyle = .black
//是否關閉拖拽
scr.isScrollEnabled = false

• 這里我們實現(xiàn)視圖的放大侯谁，縮小锌仅。
• 獲取偏移量

//加載圖片
self.loadImage(scr: scr)
        
//設置代理
scr.delegate = self
//縮放的值
scr.minimumZoomScale = 0.2
scr.maximumZoomScale = 2
        
//設置偏移量
scr.contentOffset = CGPoint(x: self.view.frame.size.width, y: 0)
        
    }
    //縮放要實現(xiàn)的方法（返回要縮放的控件）
    func viewForZooming(in scrollView: UIScrollView) -> UIView? {
        for view in scrollView.subviews {
            if view is UIImageView {
                return view
            }
        }
        return nil
    }
    
    //代理方法
    func scrollViewDidScroll(_ scrollView: UIScrollView) {
        print("任何偏移都會執(zhí)行")
        //獲取偏移量
        print(scrollView.contentOffset)
    }
    //開始拖拽
    func scrollViewWillBeginDragging(_ scrollView: UIScrollView) {
        print("開始拖拽")
        
    }
    //結(jié)束拖拽
    func scrollViewDidEndDragging(_ scrollView: UIScrollView, willDecelerate decelerate: Bool) {
        print("結(jié)束拖拽")
    }
    
    //開始減速
    func scrollViewWillBeginDecelerating(_ scrollView: UIScrollView) {
        print("開始減速")
    }
    //結(jié)束減速
    func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) {
        print("結(jié)束減速")
    }
    //加載圖片的方法
    func loadImage(scr:UIScrollView) {
        let imageV1 = UIImageView(frame: CGRect(x: 0, y: 0, width: self.view.frame.size.width, height: self.view.frame.size.height))
        imageV1.image = UIImage(named:"7.jpg")
        scr.addSubview(imageV1)
        
        let imageV2 = UIImageView(frame: CGRect(x: self.view.frame.size.width, y: 0, width: self.view.frame.size.width, height: self.view.frame.size.height))
        imageV2.image = UIImage(named:"8.jpg")
        scr.addSubview(imageV2)
        
         let imageV3 = UIImageView(frame: CGRect(x: self.view.frame.size.width * 2, y: 0, width: self.view.frame.size.width, height: self.view.frame.size.height))
        imageV3.image = UIImage(named:"10.jpg")
        scr.addSubview(imageV3)