如何在滚动tableview时获取节号

func scrollViewDidScroll(_ scrollView: UIScrollView) {
    let visibleRect = CGRect(origin: tableView.contentOffset, size: tableView.bounds.size)
    let visiblePoint = CGPoint(x: visibleRect.midX, y: visibleRect.midY)
    if let indexPath = tableView.indexPathForRow(at: visiblePoint) {
        let section = indexPath.section
        print("当前显示的节号：\(section)")
    }
}

override func scrollViewDidScroll(_ scrollView: UIScrollView) {
    if let visiblePaths = tableView.indexPathsForVisibleRows {
        for indexPath in visiblePaths {
            let section = indexPath.section
            print("当前显示的节号：\(section)")
        }
    }
}