UIView Animation is far from smooth - ios

Question

I am trying to scale a button up and down to call attention to it.
I have tried two animation methods:
method 1
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:#"transform.scale"];
animation.autoreverses = YES;
animation.repeatDuration = 2;
animation.duration = 0.4;
animation.fromValue = #(1.0f);
animation.toValue= #(1.2f);
[button.layer addAnimation:animation forKey:#"scale"];
method 2
CGAffineTransform scaleUp = CGAffineTransformMakeScale(1.2f, 1.2f);
[UIView animateWithDuration:0.5 delay:1 options:UIViewAnimationOptionAutoreverse
animations:^{
[button setTransform:scaleUp];
} completion:^(BOOL finished) {
}];
Same problem with both animations. Near the end, when the button is scaling down to its normal scale, the animation jumps directly to scale 1.0.
Something like:
1.2 ... 1.18 ... 1.15 ... boom ... 1.0
and I see the button popping from one huge scale value to 1, instead of being smooth.

Answer 1

You need to set the final state of the button.In your case,the scale change like
1.0->1.1->1.2->1.1->1.0 ->1.2(jump to final state)
Gif
CGAffineTransform scaleUp = CGAffineTransformMakeScale(1.5f, 1.5f);
[UIView animateWithDuration:0.5 delay:1 options:UIViewAnimationOptionAutoreverse
animations:^{
[self.button setTransform:scaleUp];
} completion:^(BOOL finished) {
self.button.transform = CGAffineTransformIdentity;
}];