How to Pause/Play 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.