Question

我正在尝试设计View，我可以在其中显示与Firebase数据库同步的元素。每当我的数组中的元素发生更改时，它都会重复。试图使用

self.tableView.reloadData()

但没有任何改变。也试过

self.tableView.beginUpdates()
self.tableView.reloadRowsAtIndexPaths(NSArray.init(object: indexPath) as! [NSIndexPath], withRowAnimation: .Automatic)
self.tableView.endUpdates()

它并没有像以前那样有效。我已经尝试使用函数

在主线程中执行重新加载tableView

performSelectorOnMainThread

我正在为你们发布我的代码，所以有人可以帮助我。我是iOS编程的新手，我无法弄清楚何时在tableView中重新加载数据。即使在阅读了Apple的文档之后。

override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {

    let alert = UIAlertController(title: "Akcja", message: "Wybierz akcję", preferredStyle: .ActionSheet)

    let changeFieldNumberAction = UIAlertAction(title: "Zmień numer boiska", style: .Default, handler: {(action) in

        self.showAlertOfChangingFieldNumber(indexPath)

    })

    let sendToRefereeAction = UIAlertAction(title: "Wskaż sędziego", style: .Default, handler: {(action) in
        //self.championshitTournamentMode = false

    })

    let cancelAction = UIAlertAction(title: "Anuluj", style: .Cancel, handler: nil)

    alert.addAction(cancelAction)
    alert.addAction(changeFieldNumberAction)
    alert.addAction(sendToRefereeAction)

    self.presentViewController(alert, animated: true, completion: nil)
}

func showAlertOfChangingFieldNumber(indexPath: NSIndexPath) {

    let fieldNumberAlert = UIAlertController(title: "Numer boiska", message: "Wpisz numer boiska", preferredStyle: .Alert)

    fieldNumberAlert.addTextFieldWithConfigurationHandler({(textField: UITextField!) -> Void in
        textField.placeholder = "Numer boiska"
        textField.keyboardType = UIKeyboardType.NumberPad
    })

    let saveAction = UIAlertAction(title: "Zapisz", style: .Default, handler: {(action) -> Void in

        let fieldNumberTextField = fieldNumberAlert.textFields![0] as UITextField
        let fieldNumber = Int(fieldNumberTextField.text!)
        self.updateGameFieldNumber(fieldNumber!, indexPath: indexPath)
    })

    let cancelAction = UIAlertAction(title: "Anuluj", style: .Cancel, handler: nil)

    fieldNumberAlert.addAction(cancelAction)
    fieldNumberAlert.addAction(saveAction)

    self.presentViewController(fieldNumberAlert, animated: true, completion: nil)

}

func updateGameFieldNumber(fieldNumber: Int, indexPath: NSIndexPath){

    let gameKey = games[indexPath.row].key
    let ref = FIRDatabase.database().reference().child("games").child(gameKey)

    games[indexPath.row].fieldNumber = fieldNumber
    ref.updateChildValues(games[indexPath.row].toAnyObject() as! [NSObject : AnyObject])
    //self.games.removeAtIndex(indexPath.row+1)
    self.tableView.beginUpdates()
    self.tableView.reloadRowsAtIndexPaths(NSArray.init(object: indexPath) as! [NSIndexPath], withRowAnimation: .Automatic)
    self.tableView.endUpdates()
}

我的tableView委托函数和函数用于填充基于Firebase数据库的数组，如下所示：

override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {

    let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as! GameViewCellTableViewCell

    if games[indexPath.row].fieldNumber == 0 {
        cell.fieldNumberLabel.text = "-"
    } else {
        cell.fieldNumberLabel.text = String(games[indexPath.row].fieldNumber)
    }
    cell.firstParticipantLabel.text = games[indexPath.row].firstParticipant

    cell.secondParticipantLabel.text = games[indexPath.row].secondParticipant

    cell.gameImage.image = UIImage(named: "tenisBall")

    if games[indexPath.row].completed != true {
        cell.backgroundColor = UIColor.init(red: 1, green: 109.0/255, blue: 95.0/255, alpha: 1)
    } else {
        cell.backgroundColor = UIColor.init(red: 160/255, green: 1, blue: 86/255, alpha: 1)
    }

    return cell

}

override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
    return 1
}

override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return self.games.count
}

func getGames() {

    let ref = FIRDatabase.database().reference().child("games")

    ref.observeEventType(.Value, withBlock: {snapshot in

        for item in snapshot.children {

            let gameItem = GameItem(snapshot: item as! FIRDataSnapshot)
            if(gameItem.tournamentName == self.tournamentName) {
                self.games.append(gameItem)
            }

        }
        self.tableView.reloadData()
    })

}

Answer 1

它会重复，因为您不是更新“游戏”数组中的值，而是将修改后的值附加到数组中。这发生在“getgames（）”方法中。

Answer 2

里面的

func getGames()

之后

    self.games.append(gameItem)
dispatch_async(dispatch_get_main_queue(), { 
self.tableView.reloadData()
})

无法重新加载UITableView

2 个答案: