Swift3.0 封装带有倒计时功能的按钮

初始化方法

let btn = CJSCountDownBtn(count: 5, frame: CGRect(x: 30, y: 30, width: 100, height: 50))

按钮其它属性可自行设置

// 按钮其他属性可自行设置
btn.setTitle("获取验证码", for: .normal)
btn.backgroundColor = UIColor.red
btn.setTitleColor(UIColor.black, for: .normal)

开启倒计时

// 按钮倒计时启动
btn.isCounting = true;

实现代码

import UIKit

class CJSCountDownBtn: UIButton {

    override init(frame: CGRect) {
        super.init(frame: frame)
    }
    
    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
    }
    
    /**
     便利构造器
     
     - parameter count: 倒计时总时间
     - parameter frame: 按钮frame
     
     */
    convenience init(count: Int,frame: CGRect) {

        self.init(frame: frame)
        totalTime = count
        remainingTime = count
        addTarget(self, action: #selector(btnClick), for: UIControlEvents.touchUpInside)
    }
    
    /**
     按钮内部响应事件
     */
    @objc fileprivate func btnClick() {
        
//        isCounting = true
    }
        /// 总时间
    fileprivate var totalTime = 0
        /// 剩余时间
    fileprivate var remainingTime = 0
        /// 定时器
    fileprivate var countDownTimer: Timer?
        /// 是否处于倒计时状态
    var isCounting = false {
        
        willSet {
            if newValue {
                isUserInteractionEnabled = false
                countDownTimer = Timer.scheduledTimer(timeInterval: 1, target: self, selector: #selector(updateTime), userInfo: nil, repeats: true)
            } else {
                countDownTimer?.invalidate()
                countDownTimer = nil
                isUserInteractionEnabled = true
                remainingTime = totalTime
            }
        }
    }
    /**
     计时器响应方法
     */
    @objc fileprivate func updateTime() {
        
        remainingTime -= 1
        if remainingTime > 0 {
            setTitle("\(remainingTime)秒", for: UIControlState())
        }else{
            setTitle("重新获取", for: UIControlState())
            isCounting = false
        }
    }
}