Question

Interested in creating a timer to count up for the user.

I was wondering if I’d have to keep track of all the integer variables separately or if I could use date formatter.

I’m currently using a -scheduledTimerfoo to call an -updateLabel method with seconds, but It looks a bit horrible after 100 seconds. I’d sort of like “hours:mins:seconds:split seconds” to display.

Cheers

Sam

Answer 1

NSDateFormatter is only for formatting dates, not intervals of time. A better way to do this would be to record when you start the timer, and every second, update the label with how much time passed since you started the timer.

- (void)startTimer {
    // Initialize timer, with the start date as the userInfo
    repeatTimer = [NSTimer scheduledTimerWithTimeInterval:1.0f target:self selector:@selector(updateLabel) userInfo:[NSDate date] repeats:YES];
}

- (void)updateLabel:(NSTimer *)timer {
    // Get the start date, and the time that has passed since
    NSDate *startDate = (NSDate *)[timer userInfo];
    NSTimeInterval timePassed = [[NSDate date] timeIntervalSinceDate:startDate];

    // Convert interval in seconds to hours, minutes and seconds
    int hours = timePassed / (60 * 60);
    int minutes = ((int)timePassed % (60 * 60)) / 60;
    int seconds = (((int)timePassed % (60 * 60)) % 60);
    NSString *time = [NSString stringWithFormat:@"%i:%i:%i", hours, minutes, seconds];

    // Update the label with time string
}