ios - 如何在应用程序启动时预先选择单元格？

Question

我有典型的表格 View ，有机会被选择。我想将它们选择为默认值。

import UIKit

class WeekdaysViewController: UITableViewController {
    var weekdays: [Int]!

    override func viewDidLoad() {
        super.viewDidLoad()
        tableView.tableFooterView = UIView()
        view.backgroundColor = UIColor.white
        weekdays = [1, 2, 3, 4, 5, 6, 7]
    }

    override func viewWillDisappear(_ animated: Bool) {
        performSegue(withIdentifier: Id.weekdaysUnwindIdentifier, sender: self)
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = super.tableView(tableView, cellForRowAt: indexPath)

        for weekday in weekdays {
            if weekday == (indexPath.row + 1) {
                cell.accessoryType = UITableViewCellAccessoryType.checkmark
                //cell.tintColor = UIColor(red: 13.0/255.0, green: 211.0/255.0, blue: 90.0/255.0, alpha: 1.00)
                cell.tintColor = UIColor(red: 255.0/255.0, green: 178.0/255.0, blue: 55.0/255.0, alpha: 1.00)
            }
        }
        return cell
    }

    override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        let cell = tableView.cellForRow(at: indexPath)!

        if let index = weekdays.index(of: (indexPath.row + 1)){
            weekdays.remove(at: index)
            cell.setSelected(true, animated: true)
            cell.setSelected(false, animated: true)
            cell.accessoryType = UITableViewCellAccessoryType.none
            //cell.tintColor = UIColor(red: 13.0/255.0, green: 211.0/255.0, blue: 90.0/255.0, alpha: 1.00)
            cell.tintColor = UIColor(red: 255.0/255.0, green: 178.0/255.0, blue: 55.0/255.0, alpha: 1.00)
            //cell.backgroundColor = UIColor(red: 13.0/255.0, green: 211.0/255.0, blue: 90.0/255.0, alpha: 1.00)
            //cell.tintColor = UIColor.white
        } else {
            //row index start from 0, weekdays index start from 1 (Sunday), so plus 1
            weekdays.append(indexPath.row + 1)
            cell.setSelected(true, animated: true)
            cell.setSelected(false, animated: true)
            cell.accessoryType = UITableViewCellAccessoryType.checkmark
            //cell.tintColor = UIColor(red: 13.0/255.0, green: 211.0/255.0, blue: 90.0/255.0, alpha: 1.00)
            cell.tintColor = UIColor(red: 255.0/255.0, green: 178.0/255.0, blue: 55.0/255.0, alpha: 1.00)
            //cell.backgroundColor = UIColor(red: 13.0/255.0, green: 211.0/255.0, blue: 90.0/255.0, alpha: 1.00)
            //cell.tintColor = UIColor.white
        }
    }
}

extension WeekdaysViewController {
    static func repeatText( weekdays: [Int]) -> String {
        if weekdays.count == 7 {
            return "Every Day"
        }

        if weekdays.isEmpty {
            return "No repeat"
        }

        let preferredLanguage = Locale.current.languageCode
        let locale = Locale.current.regionCode
        var ret = String()
        var weekdaysSorted:[Int] = [Int]()

        weekdaysSorted = weekdays.sorted(by: <)

        if preferredLanguage == "ru" {
            for day in weekdaysSorted {
                switch day {
                case 1:
                    ret += "Sun "
                case 2:
                    ret += "Mon "
                case 3:
                    ret += "Tue "
                case 4:
                    ret += "Wed "
                case 5:
                    ret += "Thu "
                case 6:
                    ret += "Fri "
                case 7:
                    ret += "Sat "
                default:
                    //throw
                    break
                }
            }
        } else {
            for day in weekdaysSorted {
                switch day{
                case 1:
                    ret += "Sun "
                case 2:
                    ret += "Mon "
                case 3:
                    ret += "Tue "
                case 4:
                    ret += "Wed "
                case 5:
                    ret += "Thu "
                case 6:
                    ret += "Fri "
                case 7:
                    ret += "Sat "
                default:
                    //throw
                    break
                }
            }
        }            
        return ret
    }
}

我已经在 viewDidLoad() 中添加了

weekdays = [1, 2, 3, 4, 5, 6, 7]

它几乎可以工作，但只有当我转向 WeekdaysViewController 时。

如何解决这个问题？

Answer 1

使用此代码段自动选择表格行索引。

Swift 3

tableView.selectRow(at: IndexPath(item: 1, section: 0), animated: true, scrollPosition: .middle)

Sample Image