Swift定时器的几种实现方式

方式一：

使用performSelector实现

@objc func getCodeAction(sender:UIButton) {
        count = 60
        self.performSelector(inBackground: #selector(timerThread), with: nil)
        //获取验证码
    }
    
    @objc func timerThread() {
        let timeCount = count
        for _ in 0..<timeCount {
            count = count - 1
            self.performSelector(onMainThread: #selector(updateCodeBtn), with: self, waitUntilDone: true)
            sleep(1)
        }
    }
    
    @objc func updateCodeBtn() {
        //处理更新
    }
    

方式二：

使用Timer

在iOS10后可使用

Timer.scheduledTimer(withTimeInterval: TimeInterval(1), repeats: true, block:{(timer: Timer) -> Void in
            })