// 弹性缩放动画
contentView.transform = CGAffineTransformMakeScale(0.1, 0.1);
[UIView animateWithDuration:0.5 delay:0 usingSpringWithDamping:0.7 initialSpringVelocity:0.5 options:UIViewAnimationOptionCurveEaseOut animations:^{
contentView.transform = CGAffineTransformMakeScale(1, 1);
} completion:^(BOOL finished) {
}];