聲明一個計時器

fikeprivate var countdownTimer: Timer?

計時剩余秒數

fileprivate var remainingSeconds: Int ＝0 ｛will Set ｛

UIView.beginAnimations(nil, context:nil)

UIView.setAnimationDuration(1)

self.getCodeBtn.setTitle("\(newValue)秒", for:UIControlState.normal)

UIView.commitAnimations()

ifnewValue <=0{

getCodeBtn.isEnabled=true

getCodeBtn.setTitle("重發驗證碼", for:UIControlState.normal)

}

? ? ? ｝

｝

聲明一個變量來開關計時器

fileprivate var isCounting =false{

willSet{

ifnewValue {

countdownTimer=Timer.scheduledTimer(timeInterval:1, target:self, selector:#selector(RegisterViewController.updateTime), userInfo:nil, repeats:true)

remainingSeconds=60

}else{

getCodeBtn.isEnabled=true

countdownTimer?.invalidate()

countdownTimer=nil

}

getCodeBtn.isEnabled=!newValue

}

}

@objc fileprivate func updateTime(){

remainingSeconds=remainingSeconds-1

}