UIView animateWithDuration not running second time - objective-c

Question

I've tried a lot of different options, and looked through about 15 stack answers and I just can not figure this out.
The code is basically trying to fade out, and then pop back, a view every time a tap happens. It works fine the first time, but will not work any subsequent times.
- (void)handleTap:(UIGestureRecognizer*)gestureRecognizer
{
self.view.transform = CGAffineTransformIdentity;
__block HelpScreenController* weakSelf = self;
[UIView animateWithDuration:10
delay:0
options:UIViewAnimationOptionCurveEaseOut
animations:^(void) {
weakSelf.view.alpha = 0;
}
completion:^(BOOL finished) {
if (finished) {
weakSelf.view.alpha = 100.0f;
[weakSelf.view.layer removeAllAnimations];
[weakSelf.view setNeedsDisplay];
}
}];
}
It runs perfectly the first tap - it smoothly transitions from opaque to fully transparent over a 10 second period. Second+ tap(s) it wil sit there for 10 seconds, then go transparent for a heart beat then go back to fully opaque again.
How can I get it to animate smoothly every time?
Thanks in advance!

Answer 1

alpha values are between 0.0f and 1.0f. Setting the alpha value in the completion block to 1.0f instead of 100.0f should fix the problem.
Because values larger than 1.0f are all completely opaque, you will not see the transition from 100.0f to 1.0f (99% of your animation), so the effective duration of the transition from 1.0f to 0.0f would just be about 0.1 seconds instead of 10 (not exactly, because of the animation curve, but you get the idea).

Answer 2

You could just use a CABasicAnimation instead. Try out something like this:
- (void)handleTap:(UIGestureRecognizer*)gestureRecognizer
{
CALayer *viewLayer = self.view.layer;
[viewLayer removeAllAnimations];
CABasicAnimation *fader = [CABasicAnimation animationWithKeyPath:#"opacity"];
fader.fromValue = [NSNumber numberWithFloat:0.0];
fader.toValue = [NSNumber numberWithFloat:1.0];
fader.duration = 10;//change the duration and autoreverses option to fit with your look
fader.autoreverses = YES;
fader.repeatCount = 0;
[viewLayer addAnimation:fader forKey:#"fadeAnimation"];
}
Hope it helps!