代码：
 1 CAKeyframeAnimation *animation = [CAKeyframeAnimation animationWithKeyPath:@"transform.scale"]; 2     [animation setDuration:.6]; 3     NSMutableArray *values = [NSMutableArray array]; 4     [values addObject:[NSNumber numberWithFloat:1.0]]; 5     [values addObject:[NSNumber numberWithFloat:1.2]]; 6     [values addObject:[NSNumber numberWithFloat:1.0]]; 7     [values addObject:[NSNumber numberWithFloat:1.1]]; 8     [values addObject:[NSNumber numberWithFloat:1.0]]; 9     [animation setValues:values];10     [animation setRemovedOnCompletion:YES];11     [animation setAutoreverses:NO];12     animation.timingFunction =[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];13     [_animationView.layer addAnimation:animation forKey:@"transform.scale"];