贡献者:赵大财

var cycyleTimer : Timer?    // 添加定时器    fileprivate func addCycleTimer() {        cycyleTimer = Timer(timeInterval: 2.0, target: self, selector: #selector(self.scrollToNext), userInfo: nil, repeats: true)        RunLoop.main.add(cycyleTimer!, forMode:RunLoopMode.commonModes)    }        // 移除定时器    fileprivate func removeCycleTimer() {        // 从运行循环中移除        cycyleTimer?.invalidate()        cycyleTimer = nil    }        // 定时器的方法    @objc fileprivate func scrollToNext() {        //to do    }

let displayLink = CADisplayLink(target: self, selector: #selector(update))        displayLink.add(to: RunLoop.current, forMode: RunLoopMode.defaultRunLoopMode)        displayLink.preferredFramesPerSecond = 1        displayLink.isPaused = false