swift中使用UIColllectionView实现横向轮播的一般方法
//
// HomeLiveRankCell.swift
// YYSwiftProject
//
// Created by Domo on 2018/7/28.
// Copyright © 2018年 知言网络. All rights reserved.
//
import UIKit
class HomeLiveRankCell: UICollectionViewCell {
private var multidimensionalRankVosList: [MultidimensionalRankVosModel]?
private let LiveRankCellID = "LiveRankCell"
// MARK: - 滚动排行榜
private lazy var collectionView: UICollectionView = {
let layout = UICollectionViewFlowLayout.init()
layout.sectionInset = UIEdgeInsetsMake(0, 0, 0, 0)
layout.minimumInteritemSpacing = 0
layout.minimumLineSpacing = 0
layout.itemSize = CGSize(width: (YYScreenWidth-30), height:self.frame.size.height)
// layout.sectionInset = UIEdgeInsetsMake(0, 0, 0, 0)
layout.scrollDirection = UICollectionViewScrollDirection.horizontal
let collectionView = UICollectionView.init(frame:.zero, collectionViewLayout: layout)
collectionView.contentSize = CGSize(width: (YYScreenWidth-30), height: self.frame.size.height)
collectionView.delegate = self
collectionView.dataSource = self
collectionView.backgroundColor = UIColor.white
collectionView.showsVerticalScrollIndicator = false
collectionView.showsHorizontalScrollIndicator = false
collectionView.isPagingEnabled = true
collectionView.register(LiveRankCell.self, forCellWithReuseIdentifier:LiveRankCellID)
return collectionView
}()
var timer: Timer?
override init(frame: CGRect) {
super.init(frame: frame)
self.backgroundColor = UIColor.white
self.addSubview(self.collectionView)
self.collectionView.snp.makeConstraints { (make) in
make.width.height.equalToSuperview()
make.center.equalToSuperview()
}
// 开启定时器
starTimer()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
}
// 界面赋值并刷新
var multidimensionalRankVos:[MultidimensionalRankVosModel]? {
didSet {
guard let model = multidimensionalRankVos else { return }
self.multidimensionalRankVosList = model
self.collectionView.reloadData()
}
}
}
extension HomeLiveRankCell: UICollectionViewDataSource, UICollectionViewDelegate {
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return (self.multidimensionalRankVosList?.count ?? 0)*100
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell:LiveRankCell = collectionView.dequeueReusableCell(withReuseIdentifier: LiveRankCellID, for: indexPath) as! LiveRankCell
cell.backgroundColor = UIColor.init(red: 248/255.0, green: 245/255.0, blue: 246/255.0, alpha: 1)
cell.multidimensionalRankVos = self.multidimensionalRankVosList?[indexPath.row%(self.multidimensionalRankVosList?.count)!]
return cell
}
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
print(indexPath.row%(self.multidimensionalRankVosList?.count)!)
}
/// 开启定时器
func starTimer () {
let timer = Timer.init(timeInterval: 3, target: self, selector: #selector(nextPage), userInfo: nil, repeats: true)
// 这一句代码涉及到runloop 和 主线程的知识,则在界面上不能执行其他的UI操作
RunLoop.main.add(timer, forMode: RunLoopMode.commonModes)
self.timer = timer
}
/// 在1秒后,自动跳转到下一页
@objc func nextPage() {
// 1.获取collectionView的X轴滚动的偏移量
let currentOffsetX = collectionView.contentOffset.x
let offsetX = currentOffsetX + collectionView.bounds.width
// 2.滚动该位置
collectionView.setContentOffset(CGPoint(x: offsetX, y: 0), animated: true)
}
// // 监听collectionView的滚到
// func scrollViewDidScroll(_ scrollView: UIScrollView) {
// // 1、获取滚动的偏移量 + scrollView.bounds.width * 0.5给偏移量加一半，当滑动一般就滚动pageControl的当前选中
// let offsetX = scrollView.contentOffset.x + scrollView.bounds.width * 0.5
// // 2、计算pageContra的currentIndex。这 % (cycleModelArr?.count ?? 1)也是跟上同样道理
// pageControl.currentPage = Int(offsetX / scrollView.bounds.width) % (imageArray?.count ?? 1)
// }
//
/// 当collectionView开始拖动的时候,取消定时器
func scrollViewWillBeginDragging(_ scrollView: UIScrollView) {
self.timer?.invalidate()
self.timer = nil
}
/// 当用户停止拖动的时候,开启定时器
func scrollViewWillEndDragging(_ scrollView: UIScrollView, withVelocity velocity: CGPoint, targetContentOffset: UnsafeMutablePointer<CGPoint>) {
starTimer()
}
}
//
// LiveRankCell.swift
// YYSwiftProject
//
// Created by Domo on 2018/7/28.
// Copyright © 2018年 知言网络. All rights reserved.
//
import UIKit
class LiveRankCell: UICollectionViewCell {
private lazy var imageView : UIView = {
let imageView = UIView()
return imageView
}()
private lazy var titleLabel : UILabel = {
let label = UILabel()
label.font = UIFont.systemFont(ofSize: 18)
return label
}()
private lazy var label : UILabel = {
let label = UILabel()
label.text = ">"
label.textColor = UIColor.lightGray
return label
}()
override init(frame: CGRect) {
super.init(frame: frame)
self.addSubview(self.titleLabel)
self.titleLabel.snp.makeConstraints { (make) in
make.left.equalToSuperview().offset(10)
make.height.equalTo(40)
make.width.equalTo(100)
make.centerY.equalToSuperview()
}
self.addSubview(self.imageView)
self.imageView.snp.makeConstraints { (make) in
make.right.equalToSuperview().offset(-5)
make.top.equalToSuperview().offset(5)
make.bottom.equalToSuperview().offset(-5)
make.width.equalTo(180)
}
self.imageView.addSubview(self.label)
self.label.snp.makeConstraints { (make) in
make.right.equalToSuperview().offset(-5)
make.height.width.equalTo(10)
make.centerY.equalToSuperview()
}
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
}
var multidimensionalRankVos:MultidimensionalRankVosModel? {
didSet {
guard let model = multidimensionalRankVos else { return }
self.titleLabel.text = model.dimensionName
let num:Int = (model.ranks?.count)!
let margin:CGFloat = 50
for index in 0..<num {
let picView = UIImageView.init(frame: CGRect(x:margin*CGFloat(index)+5*CGFloat(index),y:5,width:margin,height:margin))
picView.layer.masksToBounds = true
picView.layer.cornerRadius = picView.frame.size.width/2
picView.kf.setImage(with: URL(string: (model.ranks?[index].coverSmall!)!))
self.imageView.addSubview(picView)
}
}
}
}
