定时器完成后如何自动切换？

Question

我想在计时器用完时自动切换.

我在这里构建了一个计时器:

class Timer{
var timer = NSTimer();
// the callback to be invoked everytime the timer 'ticks'
var handler: (Int) -> ();
//the total duration in seconds for which the timer should run to be set by the caller
let duration: Int;
//the amount of time in seconds elapsed so far
var elapsedTime: Int = 0;
var targetController = WaitingRoomController.self


/**
:param: an integer duration specifying the total time in seconds for which the timer should run repeatedly
:param: handler is reference to a function that takes an Integer argument representing the elapsed time allowing the implementor to process elapsed time and returns void
*/
init(duration: Int , handler : (Int) -> ()){
    self.duration = duration;
    self.handler = handler;
}

/**
Schedule the Timer to run every 1 second and invoke a callback method specified by 'selector' in repeating mode
*/
func start(){
    self.timer = NSTimer.scheduledTimerWithTimeInterval(1, target: self, selector: "onTick", userInfo: nil, repeats: true);
}

/**
invalidate the timer
*/
func stop(){
    println("timer was invaidated from stop()")
    timer.invalidate();
}


/**
Called everytime the timer 'ticks'. Keep track of the total time elapsed and trigger the handler to notify the implementors of the current 'tick'. If the amount of time elapsed is the same as the total duration for the timer was intended to run, stop the timer.
*/


@objc func onTick() {
    //println("onTick")
    //increment the elapsed time by 1 second
    self.elapsedTime++;
    //Notify the implementors of the updated value of elapsed time
    self.handler(elapsedTime);
    //If the amount of elapsed time in seconds is same as the total time in seconds for which this timer was intended to run, stop the timer
    if self.elapsedTime == self.duration {
        self.stop();

    }
}
deinit{
    println("timer was invalidated from deinit()")
    self.timer.invalidate();
}

}

这是我想要执行segue以及计时器如何启动的视图控制器:

class WaitingRoomController: UIViewController {

    private func handleSetAction(someTime: String){
       countDownLabel.text = setTime;
       let duration = Utils.getTotalDurationInSeconds(someTime);
       timer = Timer(duration: duration ){
          (elapsedTime: Int) -> () in
             println("handler called")
            let difference = duration - elapsedTime;
            self.countDownLabel.text = Utils.getDurationInMinutesAndSeconds(difference)
       }
       timer.start();
    }
}

我知道auto segue的代码是:

func doSegue(){
    self.performSegueWithIdentifier("asdf", sender: self)
}

但我不知道如何将计时器和这个功能连接在一起.

Answer 1

你需要使用闭包来实现你想要的,看看我的课程Timer.

import UIKit

class Timer: NSObject {

    var counter: Int = 0
    var timer: NSTimer! = NSTimer()

    var timerEndedCallback: (() -> Void)!
    var timerInProgressCallback: ((elapsedTime: Int) -> Void)!

    func startTimer(duration: Int, timerEnded: () -> Void, timerInProgress: ((elapsedTime: Int) -> Void)!) {

       if !(self.timer?.valid != nil) {
           let aSelector : Selector = "updateTime:"

           timer = NSTimer.scheduledTimerWithTimeInterval(1, target: self, selector: aSelector, userInfo: duration, repeats: true)

           timerEndedCallback = timerEnded
           timerInProgressCallback = timerInProgress
           counter = 0
       }
    }

    func updateTime(timer: NSTimer) {

       ++self.counter
       let duration = timer.userInfo as! Int

       if (self.counter != duration) {
          timerInProgressCallback(elapsedTime: self.counter)
       } else {
          timer.invalidate()
          timerEndedCallback()
       }
    }
}

然后您可以Timer通过以下方式调用该类:

var timer = Timer()

timer.startTimer(5, timerEnded: { () -> Void in
        // Here you call anything you want when the timer finish.
        println("Finished")

        }, timerInProgress: { (elapsedTime) -> Void in
            println("\(Int(elapsedTime))")
})

上面的类在它已经有效时处理定时器的使用,并注意duration参数是updateTime使用参数传递给处理程序userInfo的timer.

我希望这对你有帮助.