心跳呼吸动画

UIView *scaleView = [[UIView alloc] initWithFrame:CGRectMake((self.view.frame.size.width - 100) / 2, 200, 100, 100)];
scaleView.backgroundColor = UIColor.blueColor;
scaleView.layer.cornerRadius = 50;
[self.view addSubview:scaleView];
//
CABasicAnimation *scaleAnimation = [CABasicAnimation animationWithKeyPath:@"transform.scale"];
scaleAnimation.duration = 0.3;
scaleAnimation.repeatCount = HUGE_VAL;
scaleAnimation.autoreverses = YES;
scaleAnimation.fromValue = [NSNumber numberWithFloat:1.1];
scaleAnimation.toValue = [NSNumber numberWithFloat:0.9];
//
[scaleView.layer addAnimation:scaleAnimation forKey:@"scale"];