(Swift)活动剩余天数倒计时

一)使用场景

多用于页面活动展示剩余天数倒计时；

• 效果如下；
• 支持后台持续计时；
• 同一个数据源，遵循代理，支持多处数据共享；

filename.gif

二)使用方法

class CCUserViewController: CCViewController, CCCountDownManageProtocol {
    
    /// 懒加载显示UILabel控件
    lazy var tipsLabel: UILabel = { UILabel() }()
    
    /// CCCountDownManage代理方法
    func refreshTime(result: [String]) {
        tipsLabel.text = "\(result[0])天,\(result[1])时,\(result[2])分,\(result[3])秒"
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // ①添加代理
        CCCountDownManage.shared.deletage = self
        // ②执行倒计时方法
        CCCountDownManage.shared.run(start: 1630302821, end: 1636302821)
        
        tipsLabel.font = MediumFont(16)
        tipsLabel.backgroundColor = .main
        tipsLabel.textAlignment = .center
        tipsLabel.layer.cornerRadius = 6
        tipsLabel.layer.masksToBounds = true
        view.addSubview(tipsLabel)
        tipsLabel.snp.makeConstraints { make in
            make.center.equalToSuperview()
            make.size.equalTo(CGSize(width: 160, height: 36))
        }
        
        // ③若初始化时,代理返回值有延迟,则可手动调用updateRemainingTime方法,优先渲染一次数据(可选行为)
        var res = [String]()
        res = CCCountDownManage.shared.updateRemainingTime()
        tipsLabel.text = "\(res[0])天,\(res[1])时,\(res[2])分,\(res[3])秒"
    }
}

三)源码分享

//
//  CCCountDownManage.swift
//  HelloSwift
//
//  Created by a51095 on 2021/7/15.
//

protocol CCCountDownManageProtocol: NSObjectProtocol {
    func refreshTime(result: [String])
}

// eg: 添加CCCountDownManage代理对象,并实现CCCountDownManageProtocol协议,协议方法中,即可获取倒计时总时长(天,时,分,秒)
final class CCCountDownManage {
    static var shared = CCCountDownManage()
    
    /// 倒计时总时长
    private var countDownTotal: Int = 0
    /// 当前系统绝对时间,进入后台后,仍持续计时
    private var startTime: Int = 0
    /// 代理对象
    public weak var deletage: CCCountDownManageProtocol?
    /// 定时器对象
    private lazy var taskTimer: DispatchSourceTimer? = {
        let timer = DispatchSource.makeTimerSource(flags: [], queue: DispatchQueue.main)
        return timer
    }()
    
    /// 开始活动倒计时
    public func run(start: Int, end: Int) {
        guard end - start > 0 else { return }
        
        countDownTotal = end - start
        startTime = Int(CACurrentMediaTime())
        
        taskTimer?.schedule(deadline: .now(), repeating: .seconds(1), leeway: .seconds(0))
        taskTimer?.setEventHandler {
            self.deletage?.refreshTime(result: self.updateRemainingTime())
        }
        taskTimer?.resume()
    }
    
    // MARK: - 获取剩余总时长
    private func remainingTime() -> Int {
        countDownTotal - (Int(CACurrentMediaTime()) - startTime)
    }
    
    /// 更新剩余总时长
    public func updateRemainingTime() -> [String] {
        var resultString = "00:00:00:00"
        let remainingTotal = remainingTime()
        if remainingTotal > 0 {
            let day = remainingTotal / (24 * 60 * 60)
            let hours = remainingTotal / (60 * 60) - day * 24
            let minutes = remainingTotal / 60 - (day * 24 * 60) - (hours * 60)
            let seconds = remainingTotal % 60
            resultString = (String(format: "%02d:%02d:%02d:%02d",day, hours, minutes, seconds))
        }else {
            taskTimer?.cancel()
        }
        return resultString.components(separatedBy: ":")
    }
    
    /// 手动停止定时器,并释放定时器对象
    public func cannel() {
        taskTimer?.cancel()
        taskTimer = nil
    }
}

四)更多组件，传送门

Demo