Swift 3.0获取验证码实现方式

声明一个计时器

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fikeprivate var countdownTimer: Timer?

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计时剩余秒数

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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("重发验证码", for:UIControlState.normal)

}

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声明一个变量来开关计时器

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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

}