swif_播图

轮播图

实现图片自动翻转（UIViewController，UIScrollViewDelegate，Timer）

import UIKit

class ViewController: UIViewController,UIScrollViewDelegate {
   var scrollerView: UIScrollView! = nil
      var pageC :UIPageControl! = nil
     var timer : Timer! = nil
    override func viewDidLoad() {
        super.viewDidLoad()
        
     let scro = UIScrollView (frame: CGRect(x: 0, y: 100, width: self.view.frame.width, height: self.view.frame.height))
       scro.contentSize = CGSize(width: self.view.frame.width*6, height: 300)
       scro.isPagingEnabled = true
        scro.bounces = false
      self.scrollerView = scro
       self.view.addSubview(scro)
       
      for index in 1...6{
           
         let name = "\(index).jpg"
           let image = UIImage(named: name)
            let x = CGFloat(index - 1) * self.view.frame.size.width
            
           let imageV = UIImageView(frame: CGRect(x: x, y: 0, width: self.view.frame.size.width, height: 300.0))
            imageV.image = image
           scro.addSubview(imageV)
        scro.delegate = self
        
        //
        let page = UIPageControl(frame: CGRect(x: 100, y:350, width: self.view.frame.size.width-200, height: 30))
        self.pageC = page
        page.numberOfPages = 6
        page.currentPage = 0
//        page.addTarget(self, action: #selector(pageAction(page:)), for:.valueChanged)
        page.addTarget(self, action: #selector(pageAction(page:)), for: .valueChanged)
        self.view.addSubview(page)
        
        //
        self.timer = Timer.scheduledTimer(timeInterval: 2, target: self, selector: #selector(timerAction), userInfo: nil, repeats: true)
        
        self.timer.fire()

        }
      
    }

    func timerAction(){
        let offser = self.scrollerView.contentOffset
        let width  = self.view.frame.size.width
         scrollerView.setContentOffset(CGPoint(x: offser.x+width, y:offser.y), animated: true)
        if scrollerView.contentOffset.x >= width*4 {
            let  point = CGPoint(x:0,y:0)
            self.scrollerView.contentOffset = point

        }
    }
func scrollViewWillBeginDragging(_ scrollView: UIScrollView) {
            
            self.timer = nil
        }
     
        func scrollViewDidEndDragging(_ scrollView: UIScrollView, willDecelerate decelerate: Bool) {
        
         self.timer = Timer.scheduledTimer(timeInterval: 1, target: self, selector: #selector(timerAction), userInfo: nil, repeats: true)
            let time =  DispatchTime.now() + 1.0
            DispatchQueue.main.asyncAfter(deadline: time){
                if let _ = self.timer {
                    
                    self.timer.fire()
                }
            }

        }
        
        
    func pageAction(page:UIPageControl) {
        let index = page.currentPage //当前第几个
        let point = CGPoint(x: CGFloat(index) * self.view.frame.size .width, y: 0)
        
        //修改偏移量
        self.scrollerView.setContentOffset(point, animated: true)
        func scrollViewDidScroll(_ scrollView: UIScrollView) {
            let x = scrollerView.contentOffset.x
            let width = self.view.frame.size.width
            if(x >= width * 4){
                self.pageC .currentPage = 0
            }else{
                self.pageC.currentPage = Int(x/width)
            }
            self.pageC.currentPage = Int(x/width)
            
        
        }
    }
}