计时器完成后如何自动切换? [英] How can I auto segue when a timer finishes?

问题描述

我想在计时器用完时自动转场.

I want to auto segue when a timer runs out.

我在这里构造了一个计时器:

I have a timer constructed here:

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();
}

}

这是我想要执行转场的视图控制器以及计时器如何启动:

This is the view controller that I want to perform the segue on and how the timer starts:

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();
    }
}

我知道自动转场的代码是:

I know that the code to auto segue is:

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

但我不知道如何将计时器和此功能连接在一起.

but I do not know how to connect the timer and this function together.

推荐答案

你需要使用闭包来实现你想要的，看我的类Timer.

You need to use closures to achieve what you want, take a look in my class 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()
       }
    }
}

然后你可以通过以下方式调用Timer类:

And then you can call the Timer class in the following way:

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))")
})

当定时器已经有效时，上面的类也处理定时器的使用，并注意到 duration 参数使用 userInfo<传递给 updateTime 处理程序timer 参数中的/code>.

The above class handle the use of the timer when it's already valid too and notice that the duration parameter is passed to the updateTime handler using the userInfo in the timer parameter.

希望对您有所帮助.

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