3.UIScrollView完整的轮播实现

请事先在storyboard中添加UIScrollView和UIPageControl控件

import UIKit

class ViewController: UIViewController {

    @IBOutlet weak var pageControl: UIPageControl!
    @IBOutlet weak var scrollView: UIScrollView!
    var images = [UIImageView]()
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        for i in 0...2{
            let name = "image\(i + 1)"
            let image = UIImageView(image: UIImage(named: name))
            image.frame = CGRectMake(self.view.frame.width * CGFloat(i), 0, self.view.frame.width, scrollView.frame.height)
            print(scrollView.frame)
            print(self.view.frame)
            image.contentMode = .ScaleAspectFit
            scrollView.addSubview(image)
            scrollView.pagingEnabled = true
            scrollView.showsHorizontalScrollIndicator = false
            scrollView.delegate = self
            images.append(image)
            pageControl.numberOfPages = images.count
            
        }
        
        scrollView.contentSize = CGSize(width: self.view.frame.width * CGFloat(images.count), height: scrollView.frame.height)
        pageControl.currentPage = 0
        
        startTimer()
    }

    @IBAction func turnPage(sender: UIPageControl) {
        stopTimer()
        toPage(pageControl.currentPage)
        resumeTimer()
    }
    
    func toPage(page:Int){
        let dx = CGFloat(page) * self.view.frame.width
        UIView.animateWithDuration(0.5, animations: {self.scrollView.contentOffset = CGPoint(x: dx, y: 0)})
    }
    
    var timer:NSTimer?
    var running = false
    func startTimer(){
        if timer == nil{
            timer = NSTimer(timeInterval: 3, target: self, selector: #selector(updateTime(_:)), userInfo: nil, repeats: true)
        }
        if !running{
            running = true
            NSRunLoop.currentRunLoop().addTimer(timer!, forMode: NSRunLoopCommonModes)
        }
    }
    func closeTimer(){
        if running{
            running = false
            timer?.invalidate()
            timer = nil
        }
    }
    func stopTimer(){
        if running{
            timer?.fireDate = NSDate.distantFuture()
        }
    }
    func resumeTimer(){
        if running{
            timer?.fireDate = NSDate(timeIntervalSinceNow: timer!.timeInterval)
        }
    }
    
    func updateTime(timer:NSTimer){
        let page = (pageControl.currentPage + 1) % images.count
        toPage(page)
        pageControl.currentPage = page
    }
    
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    
}

extension ViewController:UIScrollViewDelegate{
    
    func scrollViewDidScroll(scrollView: UIScrollView){
//        print("scroll view did scroll")
        let width = self.view.frame.width
        let page = Int((scrollView.contentOffset.x +  width / 2) / width)
        self.pageControl.currentPage = page
    }
    func scrollViewWillBeginDragging(scrollView: UIScrollView){
        print("scroll view will begin dragging")
        stopTimer()
    }

//    func scrollViewWillEndDragging(scrollView: UIScrollView, withVelocity velocity: CGPoint, targetContentOffset: UnsafeMutablePointer<CGPoint>){
//        print("scroll view will end dragging")
//    }
    
    func scrollViewDidEndDragging(scrollView: UIScrollView, willDecelerate decelerate: Bool){
        print("scroll view did end dragging")
        resumeTimer()
    }
}