var playerTimer:Timer!

建立計時器

self.playerTimer = Timer.scheduledTimer(timeInterval: 1, target: self, selector: #selector(revoleStart), userInfo: nil, repeats: true);

啟動計時器

self.playerTimer.fire()

self.playerTimer.fireDate = Date.distantFuture

計時器繼續

self.playerTimer.fireDate = Date.distantPast

計時器銷燬

self.playerTimer.invalidate()

func revoleStart (){

      // ******* 

}