[swift4.2] iOS封装发送短信验证码倒计时UIButton扩展类

示例效果图

2019-03-20 11-01-39.2019-03-20 11_02_53.gif

// 封装倒计时button
class CountDownTimerButton: UIButton {
    
    private var countdownTimer: Timer?
    // 声明闭包,在外面使用时监听按钮的点击事件
    typealias ClickedClosure = (_ sender: UIButton) -> Void
    var clickedBlock: ClickedClosure?
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        setting_init()
    }
    
    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        setting_init()
    }
    
    private func setting_init() {
        self.setTitleColor(kBlue, for: .normal)
        self.setTitle("获取验证码", for: .normal)
        self.addTarget(self, action: #selector(sendButtonClick(_:)), for: .touchUpInside)
    }
    
    var remainingSeconds: Int = 5 {
        willSet {
            self.setTitle("\(newValue) s", for: .normal)
            if newValue <= 0 {
                self.setTitle("重新获取", for: .normal)
                isCounting = false
            }
        }
    }
    var isCounting = false {
        willSet {
            // newValue 为true表示可以计时
            if newValue {
                countdownTimer = Timer.scheduledTimer(timeInterval: 1, target: self, selector: #selector(self.updateTime(_:)), userInfo: nil, repeats: true)
            } else {
                countdownTimer?.invalidate()
                countdownTimer = nil
            }
            // 设置按钮可用或不可用(按钮的isEnabled值与 newValue的值是相反的)
            self.isEnabled = !newValue
        }
    }
    
    // 按钮点击事件(在外面也可以再次定义点击事件,对这个不影响,会并为一个执行)
    @objc func sendButtonClick(_ sender: UIButton) {
        //将 isCounting 设置为true,表示可以从新计时
        isCounting = true
        if clickedBlock != nil {
            self.clickedBlock!(sender)
        }
    }
    
    @objc func updateTime(_ timer: Timer) {
        remainingSeconds -= 1
    }
    
}