重新加载后迅速保持tableview数据位置

Question

当滚动超过内容的50％时，将新数据添加到tableview ，但是问题是，在将滚动与内容一起移动到顶部之后，如何保存位置并滚动？ 更改了从底部开始的表的显示内容

func scrollViewDidEndDragging(_ scrollView: UIScrollView, willDecelerate decelerate: Bool) {
    if (self.lastContentOffset > scrollView.contentOffset.y && loadEarlierShowF) {
        let height = scrollView.frame.size.height
        let cHeight = scrollView.contentSize.height
        let contentYoffset = scrollView.contentOffset.y
        let distanceFromBottom = scrollView.contentSize.height - contentYoffset
        print(distanceFromBottom)
        let eght = cHeight / 100 * 50
        if distanceFromBottom >= eght {

            actionLoadEarlier()

        }
    }
}

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

    if (indexPath.row == 0) {
        let cell = tableView.dequeueReusableCell(withIdentifier: "RCSectionHeaderCell", for: indexPath) as! RCSectionHeaderCell
        cell.bindData(indexPath, messagesView: self)
        return cell
    }

    if (indexPath.row == 1) {
        let cell = tableView.dequeueReusableCell(withIdentifier: "RCBubbleHeaderCell", for: indexPath) as! RCBubbleHeaderCell
        cell.bindData(indexPath, messagesView: self)
        return cell
    }

    if (indexPath.row == 2) {
        let rcmessage = self.rcmessage(indexPath)
        if (rcmessage.type == RC_TYPE_STATUS) {
            let cell = tableView.dequeueReusableCell(withIdentifier: "RCStatusCell", for: indexPath) as! RCStatusCell
            cell.bindData(indexPath, messagesView: self)
            return cell
        }
        if (rcmessage.type == RC_TYPE_TEXT) {
            let cell = tableView.dequeueReusableCell(withIdentifier: "RCTextMessageCell", for: indexPath) as! RCTextMessageCell
            cell.bindData(indexPath, messagesView: self)
            let numSections = self.tableView.numberOfSections
            if numSections == 1  {
                updateTableContentInset()
            }
            return cell
        }

    }

    if (indexPath.row == 3) {
        let cell = tableView.dequeueReusableCell(withIdentifier: "RCBubbleFooterCell", for: indexPath) as! RCBubbleFooterCell
        cell.bindData(indexPath, messagesView: self)
        return cell
    }

    if (indexPath.row == 4) {
        let cell = tableView.dequeueReusableCell(withIdentifier: "RCSectionFooterCell", for: indexPath) as! RCSectionFooterCell
        cell.bindData(indexPath, messagesView: self)
        return cell
    }

    return UITableViewCell()
}
func updateTableContentInset() {
    let numSections = self.tableView.numberOfSections

    var contentInsetTop = self.tableView.bounds.size.height

    for section in 0..<numSections {
        let numRows = self.tableView.numberOfRows(inSection: section)
        let sectionHeaderHeight = self.tableView.rectForHeader(inSection: section).size.height
        let sectionFooterHeight = self.tableView.rectForFooter(inSection: section).size.height
        contentInsetTop -= sectionHeaderHeight + sectionFooterHeight
        for i in 0..<numRows {
            let rowHeight = self.tableView.rectForRow(at: IndexPath(item: i, section: section)).size.height
            contentInsetTop -= rowHeight
            if contentInsetTop <= 0 {
                contentInsetTop = 0
                break
            }
        }

        if contentInsetTop == 0 {
            break
        }
    }
    self.scrollView.contentInsetAdjustmentBehavior = .never
    self.tableView.contentInsetAdjustmentBehavior = .never
    self.tableView.contentInset = UIEdgeInsetsMake(contentInsetTop, 0, 0, 0)

}

该怎么做，将添加新数据并将滚动数据的内容保留在原处（例如电报）

曾经尝试过，但没有转移

let offset = tableView.contentOffset    
tableView.reloadData()
tableView.layoutIfNeeded()
tableView.setContentOffset(offset, animated: false)
....
let indexPath = IndexPath(row: 2, section: tableView.numberOfSections - 1)
tableView.reloadData()
tableView.layoutIfNeeded()
tableView.scrollToRow(at: indexPath, at: .top, animated: false)

Answer 1

为什么您可以尝试呢？

  func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableTest.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
    cell.textLabel?.text = arrayTemp[indexPath.row]

    if indexPath.row > (arrayTemp.count / 2) {
        callNewData()
    }
    return cell
}

您可以使用表中加载的索引来添加更多值。

当加载单元格时，您可以调用该函数以向表视图添加更多数据，因此，如果在加载5个单元格时数据以10个值开头，则在数组temp中添加更多10个itens，因此当表加载一个索引10，您称之为更多itens。