btn.transform = CGAffineTransformIdentity;
    [UIView animateKeyframesWithDuration:0.3 delay:0 options:0 animations: ^{
        [UIView addKeyframeWithRelativeStartTime:0.4 relativeDuration:0.3 animations: ^{
            CGAffineTransform transformA = CGAffineTransformMakeTranslation(0,-btn.frame.size.height * 0.03);
           CGAffineTransform transformB = CGAffineTransformScale(transformA, 1.1, 1.1);
            btn.transform = transformB;
        }];
    } completion:nil];

 

参考：

https://www.it610.com/article/1187809526427000832.htm

 

https://www.jianshu.com/p/ca7f9bc62429