如何暂停/播放 NSTimer？

Question

I need to start NSTimer by 0:0:0 that I am doing and I have a Pause button on click of that the timer has to pause after some time if a user clicks play it has to run from paused value of time. How can I pause and play in NSTimer? Any help? Thanks in advance.

Answer 1

Try this shizzle... worked great for me

EDIT

To be honest my actual code is this:

-(IBAction)clicked:(id)sender
{
    if ([startStop.titleLabel.text isEqualToString:@"Start"]) 
    {
        [startStop setTitle:@"Pause" forState:UIControlStateNormal];
        [startStop setTitleColor:[UIColor redColor] forState:UIControlStateNormal];

        timer = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(countUp) userInfo:nil repeats:YES];
        timerDown = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(countDown) userInfo:nil repeats:YES];

    } else if ([startStop.titleLabel.text isEqualToString:@"Pause"])
    {
        [startStop setTitle:@"Resume" forState:UIControlStateNormal];
        [startStop setTitleColor:[UIColor colorWithRed:0/255 green:0/255 blue:255/255 alpha:1.0] forState:UIControlStateNormal];

        pauseStart = [[NSDate dateWithTimeIntervalSinceNow:0] retain];
        previousFireDate = [[timer fireDate] retain];
        [timer setFireDate:[NSDate distantFuture]];

    } else if ([startStop.titleLabel.text isEqualToString:@"Resume"])
    {
        [startStop setTitle:@"Pause" forState:UIControlStateNormal];
        [startStop setTitleColor:[UIColor redColor] forState:UIControlStateNormal];

        float pauseTime = -1*[pauseStart timeIntervalSinceNow];
        [timer setFireDate:[NSDate dateWithTimeInterval:pauseTime sinceDate:previousFireDate]];
        [pauseStart release];
        [previousFireDate release];
    }
}

I used a UIButton and used this code when clicked.

remember to put this:

NSDate *pauseStart, *previousFireDate;

in your .h file

EDIT!

here is the countUp method. forget the down method. seconds, minutes, hours are Ints

- (void)countUp
{
    seconds += 1;

    if (seconds == 60) 
    {
        seconds = 0;
        minutes++;

        if (minutes == 60) 
        {
            minutes = 0;
            hours++;
        }
    }

}

Answer 2

You don't. Instead of pausing simply invalidate and release the old timer and when the users presses Play again, create a fresh timer.

Answer 3

refreshTimer should be on class level. Use the following code to stop the timer:

refreshTimer = [NSTimer scheduledTimerWithTimeInterval: refreshInSeconds
                                                target: self
                                              selector: @selector(refreshPage)
                                              userInfo: nil
                                               repeats: YES];
[refreshTimer invalidate];
refreshTimer = nil;

To start you can again schedule timer as Line 3

Answer 4

Use following code to start timer with arguments also:

timer = [NSTimer scheduledTimerWithTimeInterval:time target:self selector:@selector(callMyMethod:) userInfo:[NSDictionary dictionaryWithObjectsAndKeys:web1, @"web", baseURL, @"baseURL", option1, @"option", nil] repeats:NO];

and then use

[timer invalidate];

to stop the timer.

I hope this code will help you.

Thanks.

Answer 5

there is no such thing as pause for NSTimer, you have to stop and start it again.

[yourTimer invalidate]; //will stop the timer after which you can start it again

Answer 6

Updated answer for Swift 2

import UIKit

class ViewController: UIViewController {

  var myTimer = NSTimer()
  var time = 0 // global var

  @IBOutlet weak var counterLabel: UILabel!

  @IBAction func pauseTimer(sender: AnyObject) {
    myTimer.invalidate()
  }

  @IBAction func startTimer(sender: AnyObject) {
    myTimer = NSTimer.scheduledTimerWithTimeInterval(1, target: self, selector: Selector("result"), userInfo: nil, repeats: true) 
  }

  func result() {
    time++
    counterLabel.text = String(time)
    print(time) 
  }

  override func viewDidLoad() {
    super.viewDidLoad()
  }

  override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
  }
}