在willDisplayCell方法中给cell加动画

- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath{
    NSArray *arr = tableView.indexPathsForVisibleRows;
    NSIndexPath *firstIndexPath = arr[0];

    cell.layer.anchorPoint = CGPointMake(0, 0.5);
    cell.layer.position = CGPointMake(0, cell.layer.position.y);
    if (firstIndexPath.row < indexPath.row) {
        cell.layer.transform = CATransform3DMakeRotation(M_PI_4, 0, 0, 1.0);
    }else{
        cell.layer.transform = CATransform3DMakeRotation(-M_PI_4, 0, 0, 1.0);
    }

    cell.alpha = 0.0;

    [UIView animateWithDuration:1 animations:^{
        cell.layer.transform = CATransform3DIdentity;
        cell.alpha = 1.0;
    }];
}