查找最后一节和最后一行，并滚动到最后一行索引路径。

Swift 5：

let lastSection = tableView.numberOfSections - 1
let lastRow = tableView!.numberOfRows(inSection: lastSection) - 1
let lastRowIndexPath = IndexPath(row: lastRow, section: lastSection)
tableView.scrollToRow(at: lastRowIndexPath, at: .top, animated: true)

试试这个

let lastSection = groupedChats.count-1
    let lastRow = groupedChats[lastSection].count-1
    if lastSection >= 0, lastRow >= 0 {
        self.tableView.scrollToRow(at: IndexPath(row: lastRow, section: lastSection), at: .bottom, animated: true)
    }

func scrollToBottom(_ animated: Bool = true) {
        let numberOfSections = self.tblView.numberOfSections
        if numberOfSections > 0 {
            let numberOfRows = self.tblView.numberOfRows(inSection: numberOfSections - 1)
            if numberOfRows > 0 {
                let indexPath = IndexPath(row: numberOfRows - 1, section: (numberOfSections - 1))
                self.tblView.scrollToRow(at: indexPath, at: .bottom, animated: animated)
            }
        }
    }

最好创建一个可重用的扩展：

extension UITableView {

    func scrollToBottom(){

        DispatchQueue.main.async {
            let indexPath = IndexPath(
                row: self.numberOfRows(inSection:  self.numberOfSections-1) - 1,
                section: self.numberOfSections-1)
            self.scrollToRow(at: indexPath, at: .bottom, animated: true)
        }
    }
}

你可以试试这个

let lastSectionIndex = self.groupedChats.numberOfSections - 1 // last section
let lastRowIndex = self.groupedChats.numberOfRows(inSection: lastSectionIndex) - 1 // last row
self.tableView.scrollToRow(at: IndexPath(row: lastRowIndex, section: lastSectionIndex), at: .Bottom, animated: true)