表格視圖不顯示從UIAlert字段輸入的數據

Question

我的表格視圖未顯示從UIAlert字段輸入的數據。 我確定將數據傳遞到為此目的專用的[String]中，但是什么也沒有發生。 唯一的事情是，當我添加新數據時，tableView單元格分隔符在第一個和第二個Prototype單元格之間消失，但​​是什么也不顯示。 如果我繼續添加新數據，還會發生同樣的情況。 我究竟做錯了什么？ 這是整個代碼，只有一個類。

import UIKit

class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {
    @IBOutlet weak var tableView: UITableView!

    var textFields = [UITextField?]()

    var entries = [String]()
    var usernames = [String]()
    var passwords = [String]()

    override func viewDidLoad() {
        super.viewDidLoad()

        title = "Password Vault"
        navigationItem.prompt = "Add entry by clicking on the '+' sign -->"
        tableView.delegate = self
        tableView.dataSource = self

        navigationItem.rightBarButtonItem = UIBarButtonItem(barButtonSystemItem: .Add, target: self, action: "addEntry")
        navigationItem.leftBarButtonItem = UIBarButtonItem(barButtonSystemItem: .Edit, target: self, action: "edit")
    }

    func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {

        return entries.count
    }

    func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCellWithIdentifier("cell", forIndexPath: indexPath)
        cell.textLabel?.text = entries[indexPath.row]
        cell.accessoryType = .DetailDisclosureButton
        cell.selectionStyle = .Blue
        tableView.reloadData()

        return cell
    }
    func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
        tableView.cellForRowAtIndexPath(indexPath)
    }

    func tableView(tableView: UITableView, didDeselectRowAtIndexPath indexPath: NSIndexPath) {
    }

    func tableView(tableView: UITableView, canEditRowAtIndexPath indexPath: NSIndexPath) -> Bool {

        return true
    }

    func tableView(tableView: UITableView, commitEditingStyle editingStyle: UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath) {
        if editingStyle == .Delete {
            entries.removeAtIndex(indexPath.row)
            tableView.reloadData()
        }
    }

    func tableView(tableView: UITableView, accessoryButtonTappedForRowWithIndexPath indexPath: NSIndexPath) {

        let ac = UIAlertController(title: "Details for \(self.entries[indexPath.row])", message: nil, preferredStyle: .Alert)
        ac.addAction(UIAlertAction(title: "username: \(self.usernames[indexPath.row]) ", style: .Default, handler: nil))
        ac.addAction(UIAlertAction(title: "password: \(self.passwords[indexPath.row])", style: .Default, handler: nil))
        ac.addAction(UIAlertAction(title: "OK", style: .Default, handler: nil))

        presentViewController(ac, animated: true, completion: nil)
    }

    func entry(textField: UITextField!) -> Void {
        textField.placeholder = "enter entry name"
        textFields.append(textField)

    }

    func username(textField: UITextField!) ->Void {
        textField.placeholder = "enter username"
        textFields.append(textField)

    }

    func password(textField: UITextField!) -> Void {
        textField.placeholder = "enter password"
        textFields.append(textField)
    }

    func addEntry() {
        let ac = UIAlertController(title: "New Entry", message: "Enter entry name, username and password", preferredStyle: .Alert)
        ac.addTextFieldWithConfigurationHandler(entry)
        ac.addTextFieldWithConfigurationHandler(username)
        ac.addTextFieldWithConfigurationHandler(password)
        ac.addAction(UIAlertAction(title: "OK", style: .Default) {[unowned self] _ in
            self.entries.append(self.textFields[0]!.text!)
            self.usernames.append(self.textFields[1]!.text!)
            self.passwords.append(self.textFields[2]!.text!)
            self.tableView.reloadData()
            self.textFields.removeAll()
        })

        ac.addAction(UIAlertAction(title: "Cancel", style: .Cancel, handler:nil))

        presentViewController(ac, animated: true, completion: nil)

        navigationItem.leftBarButtonItem = UIBarButtonItem(barButtonSystemItem: .Edit, target: self, action: "edit")
    }

    func edit() {
        tableView.editing = true
        navigationItem.leftBarButtonItem = UIBarButtonItem(barButtonSystemItem: .Done, target: self, action: "doneEditing")

    }

    func doneEditing() {
        tableView.editing = false
        navigationItem.leftBarButtonItem = UIBarButtonItem(barButtonSystemItem: .Edit, target: self, action: "edit")
    }

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

Answer 1

您有一個永無休止的reloadData（）循環。 如果使用當前的實現在此方法中設置一個斷點，則會注意到它是連續執行的。 該單元從未出現，因為它一直在嘗試重新加載它。

您的索引路徑的方法單元格應如下所示

func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCellWithIdentifier("cell", forIndexPath: indexPath)
    cell.textLabel?.text = entries[indexPath.row]
    cell.accessoryType = .DetailDisclosureButton
    cell.selectionStyle = .Blue
    return cell
}