重新加载表数据时出现致命错误：展开为零：需要帮助

Posted 2023-03-11

【中文标题】重新加载表数据时出现致命错误：展开为零：需要帮助

【英文标题】：fatal error when reloading table data: unwraps to nil: need assistance

【发布时间】：2015-07-11 04:20:13

【问题描述】：

我正在开发的应用程序有一个表格视图。似乎我在打印表格视图单元格值时犯了一个错误，因为每当我在应用程序运行时重新加载表格数据时，我都会收到一个致命错误，在展开时意外发现 nil。发生这种情况是因为表代码中有错误。帮助将不胜感激，谢谢。 完整代码： 导入 UIKit

class ViewController: UIViewController, UITableViewDelegate 
var arr = [Int]()
var timer = NSTimer()
var countdowntimer = NSTimer()
var count = 0
var countdown = Int(arc4random_uniform(4000) + 1000)
var highscore:Int!
var buttonTapCounter = 0
let dateFormatter = NSDateFormatter()


@IBOutlet weak var beginButton: UIButton!


@IBOutlet weak var table: UITableView!
@IBOutlet weak var resetDataButton: UIButton!
@IBOutlet weak var averageLabel: UILabel!
@IBOutlet weak var bestLabel: UILabel!





@IBOutlet weak var startButton: UILabel!
@IBOutlet weak var highScoreButton: UILabel!
@IBOutlet weak var timerLabel: UILabel!
@IBOutlet weak var backgroundImage: UIImageView!

func updateTime() 
    countdown = countdown - 1
    if countdown <= 0 
        startButton.textColor = UIColor.blackColor()
        startButton.text = "Tap Now!"
        countdowntimer.invalidate()
        backgroundImage.image = UIImage(named: "red")
        count = 0
        Timer()
    


func Timer() 
    timer = NSTimer.scheduledTimerWithTimeInterval(0.001, target:self, selector:Selector("reflexTest"), userInfo:nil, repeats: true)



func reflexTest() 
    count = count + 1
    timerLabel.text = "\(count) ms"




@IBAction func returnPressed(sender: AnyObject) 
    buttonTapCounter = 0



@IBAction func scoreButtonTouched(sender: AnyObject) 
    buttonTapCounter = 0
    table.reloadData()
//THE table.reloadData() UP HERE IS CAUSING THE PROBLEM.
//I AM TYPING
//LIKE THIS SO YOU WILL
//NOTICE AS YOU SCROLL
//SORRY
//I AM TYPING
//LIKE THIS SO YOU WILL
//NOTICE AS YOU SCROLL
//SORRY


@IBAction func beginTapped(sender: AnyObject) 
    if startButton.text == "Tap when the Color Changes" 
        startButton.text = "You tapped too early!"
        countdowntimer.invalidate()
        countdown = Int(arc4random_uniform(4000) + 1000)
     else 
        if count == 0 
            countdowntimer = NSTimer.scheduledTimerWithTimeInterval(0.001, target: self, selector: Selector("updateTime"), userInfo: nil, repeats: true)
            startButton.text = "Tap when the Color Changes"
            countdown = Int(arc4random_uniform(4000) + 1000)
            timerLabel.text = "\(count) ms"
         else 
            timer.invalidate()
            backgroundImage.image = UIImage(named: "green")
            startButton.text = "Tap to Begin"
            arr.append(count)
            count = 0
            highscore = minElement(arr)
            highScoreButton.text = "Best: \(highscore)"
            saveDefaults()

        

    



func loadDefaults() 

    if let savedArray = NSUserDefaults.standardUserDefaults().objectForKey("data") as? [Int] 
    self.arr = savedArray
    

func saveDefaults() 
    NSUserDefaults.standardUserDefaults().setObject(self.arr, forKey: "data")


func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int 
    return arr.count


func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell 
    dateFormatter.dateFormat = "MM/dd/yy HH:mm"
    let dateInFormat = dateFormatter.stringFromDate(NSDate())

    let cell = UITableViewCell(style: UITableViewCellStyle.Default, reuseIdentifier: "Cell")
    var tableArray:[Int]! = arr
    cell.textLabel?.text = String(tableArray[indexPath.row])

    return cell



override func viewDidLoad() 
    super.viewDidLoad()
    loadDefaults()

    highscore = minElement(arr)
    if buttonTapCounter == 0 
        highScoreButton.text = "Best: \(highscore)"
    



    // Do any additional setup after loading the view, typically from a nib.


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

需要修复的代码大概就是这个块：

 func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell 
    dateFormatter.dateFormat = "MM/dd/yy HH:mm"
    let dateInFormat = dateFormatter.stringFromDate(NSDate())

    let cell = UITableViewCell(style: UITableViewCellStyle.Default, reuseIdentifier: "Cell")
    var tableArray:[Int]! = arr
    cell.textLabel?.text = String(tableArray[indexPath.row])

    return cell

再次感谢大家，请记住：展开可选值时发现的错误 nil 与表格有关。谢谢！

【问题讨论】：

不。不起作用:(。问题出在 String(tableArray[indexPath.row]) 的某个地方 ..它在那里展开时发现了一个错误。这意味着我很可能必须在某处添加一个解释标记，我不知道在哪里，我遇到了麻烦。

记录您的 tableArray 并检查它是否为零....

这样做的目的是什么：var tableArray:[Int]！ = arr ?

【参考方案1】：

我认为问题出在您的数组（arr）上。在控制台中打印 arr。 我通过采用静态整数数组尝试了您的代码，它工作正常。