Scale a circle at same center position - ios

Question

I am working on scaling the circle and keep the same center position, which looks like the pulsing circle on map.
AnimationView.m
#property (nonatomic, strong) UIBezierPath *ovalPath;
- (void)drawCircle
{
UIGraphicsBeginImageContext(self.frame.size);
CGRect rect = CGRectMake(25.45, 49.25, 5.8, 5.8);
self.ovalPath = [UIBezierPath bezierPathWithOvalInRect: rect];
[self.ovalPath fill];
UIGraphicsEndImageContext();
}
- (void)bumpUpCircle
{
CAShapeLayer *pathLayer = [CAShapeLayer layer];
pathLayer.frame = self.bounds;
pathLayer.path = self.ovalPath.CGPath;
pathLayer.fillColor = [UIColor blackColor].CGColor;
pathLayer.lineWidth = 2.0f;
pathLayer.lineJoin = kCALineJoinBevel;
[self.layer addSublayer:pathLayer];
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:#"transform.scale"];
animation.fromValue = [NSValue valueWithCATransform3D:CATransform3DMakeScale(0.0, 0.0, 0)];
animation.toValue = [NSValue valueWithCATransform3D:CATransform3DMakeScale(10.0, 10.0, 10.0)];
animation.repeatCount = 1;
animation.removedOnCompletion = NO;
animation.fillMode = kCAFillModeForwards;
animation.duration = 1;
animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut];
[pathLayer addAnimation:animation forKey:#"transform.scale"];
NSLog(#"%#",NSStringFromCGPoint(self.bounds.origin));
}
However, the scaling position is in a strange position, rather than the center of the circle.
Any ideas will be very appreciated. Thanks.
Edit:
GIF uploaded

Answer 1

My suggestion for you with a pulsing circle, is to use an UIView and add it as a subview in your UIViewController. In following example you get a pulsing circle (a UIView with a cornerRadius like the radius) scaling up and down in a very few lines. Include this e.g. in your UIViewController's viewDidLoad to try it out.
int radius = 100;
UIView * circleView = [[UIView alloc] init];
circleView.backgroundColor = [UIColor greenColor];
circleView.frame = CGRectMake(0, 0, radius*2, radius*2);
circleView.center = self.view.center;
circleView.layer.cornerRadius = radius;
[self.view addSubview:circleView];
[UIView animateWithDuration:0.8f
delay:0.0f
options:UIViewAnimationOptionAutoreverse | UIViewAnimationOptionRepeat
animations:^{
circleView.transform = CGAffineTransformMakeScale(1.1, 1.1);
} completion:^(BOOL fin) {
// Do nothing
}];