NSTimer periodic task doesn't get called while scrolling
ios, nstimer, scroll
Solution
You'll need to add your timer to the UITrackingRunLoopMode to make sure your timer also fires during scrolling.
NSRunLoop *runloop = [NSRunLoop currentRunLoop];
NSTimer *timer = [NSTimer timerWithTimeInterval:0.1 target:self selector:@selector(myTimerAction:) userInfo:nil repeats:YES];
[runloop addTimer:timer forMode:NSRunLoopCommonModes];
[runloop addTimer:timer forMode:UITrackingRunLoopMode];
From: https://stackoverflow.com/a/1997018/474896
Problem
I have an NSTimer ``` timer = [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(periodicTimer) userInfo:nil repeats:YES]; ``` which does ``` - (void)periodicTimer { NSLog(@"Bang!"); if (timerStart != nil) [timerLabel setText:[[NSDate date] timeDifference:timerStart]]; } ``` The problem is that while scrolling a tableview (or doing other tasks) the label doesn't get updated, furthermore, "Bang!" doesn't appear, so I supposed the method doesn't get called. My question is how to update the label periodically even when the user is playing around with the app interface.