http://m.itdecent.cn/p/583ca675065a

import UIKit
class XTimer: NSObject {
    var ti:TimeInterval!
    var atarget:AnyObject!
    var aSelector:Selector!
    var userInfo:Any?
    private var isValid = true
    private var yesOrNo = true
    override init() {
        super.init()
    }
    class func scheduledTimer(timeInterval ti:TimeInterval,target aTarget:Any,selector aSelector:Selector,userInfo:Any?,repeats yesOrNo:Bool)->XTimer{
        let timer = XTimer()
        timer.ti =  ti
        timer.atarget = aTarget as AnyObject!
        timer.aSelector = aSelector
        timer.userInfo = userInfo
        if yesOrNo{
            timer.repeatSelector()
        }else{
            let popTime = DispatchTime.now() + ti
            DispatchQueue.main.asyncAfter(deadline: popTime) {
                (aTarget as AnyObject!).performSelector(onMainThread: aSelector, with: userInfo, waitUntilDone: false)
            }
        }
        return timer
    }
    func repeatSelector(){
        let popTime = DispatchTime.now() + ti
        DispatchQueue.main.asyncAfter(deadline: popTime) {
            if self.yesOrNo{
                (self.atarget as AnyObject!).performSelector(onMainThread: self.aSelector, with: self.userInfo, waitUntilDone: false)
            }
            if self.isValid{
                self.repeatSelector()
            }
        }
    }
    func reStart(){
        yesOrNo = true
    }
    func stop(){
        yesOrNo = false
    }
    func invalidate(){
        isValid = false
    }
}