Попробуйте:
- (void)blinkAnimation:(NSString *)animationID finished:(BOOL)finished target:(UIView *)target
{
NSString *selectedSpeed = [[NSUserDefaults standardUserDefaults] stringForKey:@"EffectSpeed"];
float speedFloat = (1.00 - [selectedSpeed floatValue]);
[UIView beginAnimations:animationID context:target];
[UIView setAnimationDuration:speedFloat];
[UIView setAnimationDelegate:self];
[UIView setAnimationDidStopSelector:@selector(blinkAnimation:finished:target:)];
if([target alpha] == 1.0f)
[target setAlpha:0.0f];
else
[target setAlpha:1.0f];
[UIView commitAnimations];
}
Вызовите мою функцию на UILabel:
[self blinkAnimation:@"blinkAnimation" finished:YES target:labelView];