import UIKit

private let CycleCellID = "CycleCellID"

class BannerCycleView: UIView {

var layout  : UICollectionViewFlowLayout!

var collectionView :UICollectionView!

var pageContol : UIPageControl?

var cycleTimer : Timer?

let timeInterval : TimeInterval = 2

var cycleModels : [CycleModel]? {

didSet {

collectionView.reloadData()

pageContol?.numberOfPages = cycleModels?.count ?? 0

let indexPath = IndexPath(item: (cycleModels?.count ?? 0) * 100, section: 0)

collectionView.scrollToItem(at: indexPath, at: .left, animated: false)

removeCycleTimer()

addCycleTimer()

}

}

override init(frame: CGRect) {

super.init(frame: frame)

setupUI()

}

required init?(coder aDecoder: NSCoder) {

fatalError("init(coder:) has not been implemented")

}

}

extension BannerCycleView {

func  setupUI() {

self.layout = UICollectionViewFlowLayout()

self.layout.itemSize = CGSize(width: kScreenW, height: 200)

self.layout.minimumLineSpacing = 0

self.layout.minimumInteritemSpacing = 0

self.layout.scrollDirection = .horizontal

self.collectionView = UICollectionView.init(frame: self.bounds, collectionViewLayout: self.layout)

self.collectionView.isPagingEnabled = true

self.collectionView.showsHorizontalScrollIndicator = false

self.collectionView.delegate = self

self.collectionView.dataSource = self

self.collectionView .register(CollectionCycleCell.self, forCellWithReuseIdentifier: CycleCellID)

self.collectionView.backgroundColor = UIColor.white

self.addSubview(self.collectionView)

self.pageContol = UIPageControl(frame: CGRect(x: self.collectionView.center.x - 50 , y: 130, width: 100, height: 20))

self.addSubview(self.pageContol!)

}

}

extension BannerCycleView : UICollectionViewDataSource {

func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {

return (cycleModels?.count ?? 0) * 10000

}

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {

let cell = collectionView.dequeueReusableCell(withReuseIdentifier: CycleCellID, for: indexPath) as! CollectionCycleCell

print(cycleModels![indexPath.item % cycleModels!.count])

cell.cycleModel = cycleModels![indexPath.item % cycleModels!.count]

return cell

}

}

extension BannerCycleView : UICollectionViewDelegate {

func scrollViewDidScroll(_ scrollView: UIScrollView) {

// 计算偏移量

let offsetX = scrollView.contentOffset.x + scrollView.bounds.width * 0.5

// 计算页码当前页

pageContol?.currentPage = Int(offsetX / scrollView.bounds.width) % (cycleModels?.count ?? 1)

}

func scrollViewWillBeginDragging(_ scrollView: UIScrollView) {

removeCycleTimer()

}

func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) {

addCycleTimer()

}

}

extension BannerCycleView {

fileprivate func addCycleTimer(){

cycleTimer = Timer(timeInterval: 2.0, target: self, selector: #selector(self.scrollToNext), userInfo: nil, repeats: true)

RunLoop.main.add(cycleTimer!, forMode: .commonModes)

}

fileprivate func removeCycleTimer(){

cycleTimer?.invalidate()

cycleTimer = nil

}

@objc fileprivate func scrollToNext() {

collectionView.setContentOffset(CGPoint(x:collectionView.contentOffset.x + collectionView.bounds.width , y:0), animated: true)

}

}

// ------ CollectionCycleCell

import UIKit

class CollectionCycleCell: UICollectionViewCell {

var iconImageView: UIImageView!

var titleStringLabel : UILabel!

func setupUI() {

self.backgroundColor = UIColor.white

self.iconImageView = UIImageView()

self.iconImageView.frame = CGRect(x: 0, y: 0, width: kScreenW, height: 200)

self.titleStringLabel = UILabel()

self.titleStringLabel.text = ""

self.titleStringLabel.font = UIFont.systemFont(ofSize: 13)

self.titleStringLabel.frame = CGRect(x:  0, y:  163, width: iconImageView.frame.width, height: 20)

self.titleStringLabel.backgroundColor = UIColor.lightGray.withAlphaComponent(0.8)

self.addSubview(iconImageView)

self.iconImageView.addSubview(self.titleStringLabel)

}

override init(frame: CGRect) {

super.init(frame: frame)

setupUI()

}

required init?(coder aDecoder: NSCoder) {

fatalError("init(coder:) has not been implemented")

}

// MARK: 定义模型属性

var cycleModel : CycleModel? {

didSet {

titleStringLabel.text = cycleModel?.title

let iconURL = URL(string: cycleModel?.bigimg ?? "")!

iconImageView.kf.setImage(with: iconURL, placeholder: UIImage(named: "homepage_refresh_tv"))

}

}

}

//---- model

import UIKit

class CycleModel: NSObject {

var title : String = ""

var smallimg : String = ""

var bigimg : String = ""

init(dict : [String : Any]) {

super.init()

setValuesForKeys(dict)

}

override func setValue(_ value: Any?, forUndefinedKey key: String) {}

}

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