下面一段代码给大家分享swift 3.0 实现短信验证码倒计时功能，具体实例代码如下所示：

? 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 class TCCountDown { private var countdownTimer: Timer? var codeBtn = UIButton() private var remainingSeconds: Int = 0 { willSet { codeBtn.setTitle("重新获取\(newValue)秒", for: .normal) if newValue <= 0 { codeBtn.setTitle("获取验证码", for: .normal) isCounting = false } } } var isCounting = false { willSet { if newValue { countdownTimer = Timer.scheduledTimer(timeInterval: 1, target: self, selector: #selector(self.updateTime), userInfo: nil, repeats: true) remainingSeconds = 60 codeBtn.setTitleColor(BtnCodeColor, for: .normal) } else { countdownTimer?.invalidate() countdownTimer = nil codeBtn.setTitleColor(MainColor, for: .normal) } codeBtn.isEnabled = !newValue } } @objc private func updateTime() { remainingSeconds -= 1 } } //调用方法 var countDown = TCCountDown()//实例化 countDown.isCounting = true//开启倒计时

以上所述是小编给大家介绍的swift 3.0 实现短信验证码倒计时功能，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对服务器之家网站的支持！

原文链接：http://blog.csdn.net/qq_25592881/article/details/56671945