Question

Possible Duplicate:
UIScrollView pauses NSTimer until scrolling finishes

I have a scrollview and a label to show the countdown to date. I got the countdown working but whenever I drag the scrollview up and down the countdown stopped but when I release my finger it started working again. I know it has to do with muti-threading. Here is my code

-(void) viewdidload
{
    timer = [NSTimer scheduledTimerWithTimeInterval:0 target:self selector:@selector(updateLabel) userInfo:nil repeats:YES];
}

-(void)updateLabel {


    NSCalendar *calender = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];

    NSDateComponents *countdown = [calender  
                                   components:(NSDayCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit) 
                                   fromDate:[NSDate date] 
                                   toDate:destDate 
                                   options:0];

    timerCountDown.text = [NSString stringWithFormat:@"%dday %dh %dm %ds", [countdown day],[countdown hour],[countdown minute],[countdown second]];
}

Answer 1

You set the text to the UILabel by the following way.

NSString *cntTime = [NSString stringWithFormat:@"%dday %dh %dm %ds", [countdown day],[countdown hour],[countdown minute],[countdown second]];
[timerCountDown performSelectorOnMainThread:@selector(setText:) withObject:cntTime waitUntilDone:YES];

Edit:

The method should be -(void)viewDidLoad.

Also , give some time interval, say 1 sec,

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

And, are u implementing any UIScrollViewDelegate methods?