ios – WKInterfaceTimer用作倒计时开始和停止的计时器

我正在尝试创建一个倒计时x分钟和y秒的计时器.
我正在计算秒数并创建InterfaceTimer,如下所示：
timer.setDate(NSDate(timeIntervalSinceNow：Double(secondsValue 1)))
timer.stop()

在那之后我一直停下来并一次又一次地启动它,但是随着“时间(现在)不停止”,值突然减少.
例如：如果计时器显示：55,我启动它3秒并停止它,它显示：52,我等待10秒然后再次启动它,它从42开始.

我无法保存当前在WKInterfaceTimer中的值,因此我可以从同一点重新开始.我试过的一切都行不通.有没有人使用计时器,它停止后保持相同的值？

解决方法

是的,Watchkit计时器有点……笨拙……绝对不是很直观.但那只是我的个人意见

每次用户选择恢复计时器时,您都必须继续设置日期/计时器.

请记住,您还需要一个内部NSTimer来跟踪事物,因为当前的WatchKit计时器只是用于显示而没有附加任何真正的逻辑.

也许这样的事情……它不优雅.但它的确有效

@IBOutlet weak var WKTimer: WKInterfaceTimer! //watchkit timer that the user will see

        var myTimer : NSTimer?  //internal timer to keep track 
        var isPaused = false //flag to determine if it is paused or not
        var elapsedtime : NSTimeInterval = 0.0 //time that has passed between pause/resume
        var startTime = NSDate()
        var duration : NSTimeInterval = 45.0 //arbitrary number. 45 seconds

       override func willActivate(){
           super.willActivate()
           myTimer = NSTimer.scheduledTimerWithTimeInterval(duration,target: self,selector: Selector("timerDone"),userInfo: nil,repeats: false)
           WKTimer.setDate(NSDate(timeIntervalSinceNow: duration ))
            WKTimer.start()
       }

    @IBAction func pauseResumepressed() {
        //timer is paused. so unpause it and resume countdown
        if isPaused{
            isPaused = false
            myTimer = NSTimer.scheduledTimerWithTimeInterval(duration - elapsedtime,repeats: false)
            WKTimer.setDate(NSDate(timeIntervalSinceNow: duration - elapsedtime))
            WKTimer.start()
            startTime = NSDate()
            pauseResumeButton.setTitle("Pause")


          }
          //pause the timer
          else{
                isPaused = true

                //get how much time has passed before they paused it
                let paused = NSDate()
                elapsedtime += paused.timeIntervalSinceDate(startTime)

                //stop watchkit timer on the screen
                WKTimer.stop()

                //stop the ticking of the internal timer
                myTimer!.invalidate()

                //do whatever UI changes you need to
                pauseResumeButton.setTitle("Resume")
            }
        }

      func timerDone(){
           //timer done counting down
      }