tableview-animation

tableview滚动时产生缩放动画

####效果如图

#####核心代码如下

- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
    CGFloat viewHeight = scrollView.bounds.size.height + scrollView.contentInset.top;
    for (TableViewCell *cell in [self.tableview visibleCells]) {
        CGFloat y = cell.centerY - scrollView.contentOffset.y;
        CGFloat p = y - viewHeight / 2;
        CGFloat scale = cos(p / viewHeight * 0.9) * 0.95;
        [UIView animateWithDuration:0.15 delay:0 options:UIViewAnimationOptionCurveEaseInOut | UIViewAnimationOptionAllowUserInteraction | UIViewAnimationOptionBeginFromCurrentState animations:^{
            cell.image.transform = CGAffineTransformMakeScale(scale, scale);
        } completion:NULL];
    }
}