编辑代码

func getCurrentTimeStamp() -> Int {
     let now =Date()
     let timeInterval : timeInterval = now.timeIntervalSincel1970
     return Int(timeInterval)
 }
 func timeElapse(){
    Timer.scheduledTimer(withTimeInterval: 0.5, repests: true){
        (timer) in
        let timestamp = self.getCurrentTimeStamp()
        let pastPeriod = timestamp - self.beginTimestamp
        let countDown = self.GamePeriod - pastPeriod
        self.TimeCost = pastPeriod
        if countDown <= 0 || self .GameOver{
            self.GameOver = true
            let tipsLabel = self.view.viewWithTag(1001) as! UIILabel
            tipsLabel.text = "游戏结束,共消耗时间\(self.TimeCost)秒"
            timer.invalidate()
        }
        let tipsLabel = self. view.viewWithTag(1002) as! UIILabel
        DispatchQueue.main.async{
            tipsLabel.text ="您消耗\(pastPeriod)秒,倒计时\(countDown)秒"
        }
    }
 }