UITableView在设备旋转后保持滚动位置

var lastContentOffset: CGPoint = .zero

func scrollViewDidScroll(_ scrollView: UIScrollView) {
    lastContentOffset = scrollView.contentOffset
}

override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
    super.viewWillTransition(to: size, with: coordinator)
    
    coordinator.animate(alongsideTransition: { _ in
        // 获取旋转前的可见行的索引路径
        if let indexPathsForVisibleRows = self.tableView.indexPathsForVisibleRows,
           let firstVisibleIndexPath = indexPathsForVisibleRows.first {
            let rect = self.tableView.rectForRow(at: firstVisibleIndexPath)
            let convertedRect = self.tableView.convert(rect, to: self.tableView.superview)
            let contentOffsetY = convertedRect.origin.y - self.tableView.contentInset.top
            self.lastContentOffset = CGPoint(x: 0, y: contentOffsetY)
        }
    }, completion: { _ in
        // 恢复滚动位置
        self.tableView.scrollToRow(at: IndexPath(row: 0, section: 0), at: .top, animated: false)
        self.tableView.contentOffset = self.lastContentOffset
    })
}