如何通過在NsUserDefaults中將數據保存爲數組來記住遊戲狀態

Question

我已經構建了一個名爲Mad Lib的簡單應用程序。在這裏你輸入一個單詞11次到文本框中。單詞被附加到名爲wordStack的列表中。你點擊OK按鈕，準備讓segway把用戶帶到第二個屏幕。在這裏，這11個單詞被作爲字符串填充到文本中。

的第二頁上的txt例：「泰山也被稱爲（wordStack [1]）」

所以，我讀似乎訪問屬性的用戶默認當內容是不變的，也很用於簡單數據如單個字符串或可能是一個整數。我有一個很難得到這個與這個數組一起工作。

所以還挺除了事實

var wordStack: [String] = [] 

復位workstack每次工作。

任何幫助我解決問題的解決方案都是絕對的英雄！謝謝！

import UIKit 

class ViewController: UIViewController { 

    override func viewDidLoad() { 
    super.viewDidLoad() 
    if let s = userDefault.valueForKey("wordstack"){ 
     var wordStack: [String] = [] 
     for i in s as! NSArray { 
      print(i) 
      wordStack.append(String(i)) 
      print(wordStack) 
     } 
    } 

    print(wordStack) 

    // 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. 
    } 

    @IBOutlet weak var guess: UILabel! 

    @IBOutlet weak var textField: UITextField! 

    // Save game state. 
    var userDefault = NSUserDefaults.standardUserDefaults() 

    // Saves the user's input. 
    var wordStack: [String] = [] 

    func test() { 
    let userInput = textField.text 
    textField.text = nil 
    if wordStack.count < 10 { 
     wordStack.append(userInput!) 
     guess.text = "\(11-wordStack.count) guesses left!" 
     userDefault.setValue(wordStack, forKey: "wordstack") 
    } else { 
     wordStack.append(userInput!) 
    } 
    } 

    // When pressed enter in the textfield append the input to workstack and refresh textfield for new input. 
    @IBAction func enterTextField(sender: AnyObject) { 
    test() 
    } 

    @IBAction func buttonClick(sender: AnyObject) { 
    if wordStack.count <= 10 { 
     let alertController = UIAlertController(title: "Wacht", message: "Je bent nog niet klaar. \(wordStack.count)/11 woorden ingevuld.",preferredStyle: UIAlertControllerStyle.Alert) 
     alertController.addAction(UIAlertAction(title: "Ok", style: UIAlertActionStyle.Default,handler: nil)) 
     self.presentViewController(alertController,animated: true, completion: nil) 
    } 
    } 

    override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) { 
    let secondViewController: ViewController2 = segue.destinationViewController as! ViewController2 
    if wordStack.count > 10 { 
    secondViewController.outputMessage = "One of the most silly characters is named Tarzan of the bees. Tarzan is raised by an/a \(wordStack[0]) and lives in the \(wordStack[1]) in the heart of the darkest \(wordStack[2]). He spent most of his time eating \(wordStack[3]) and swinging from tree to \(wordStack[4]). Whenever he gets angry he beats on his chest and says \(wordStack[5])! This is his way cry. Tarzan always dresses in smelly \(wordStack[6]) shorts made of the skin of an/a \(wordStack[7]) and his best friend is an/a \(wordStack[8]) Chimpanzee called Cheetah. He is supposed to be able to speak to elephants and \(wordStack[9]). In the movies, Tarzan plays \(wordStack[10])" 

    // reset guesses 
    //var count: Int = 0 
    } 
    } 
} 

Answer 1

的問題是，你聲明一個局部變量wordStack這是不相同的具有相同名稱的實例屬性。

即使在讀取用戶默認值時，使用var聲明的變量始終是可變的。

簡單的辦法是在viewDidLoad()

更好的解決方案wordStack之前刪除var關鍵字：

註冊在AppDelegateapplicationDidFinishLaunching鍵/值對

let defaults = NSUserDefaults.standardUserDefaults() 
let defaultValues = ["wordstack" : [String]()] 
defaults.registerDefaults(defaultValues) 

然後，只需更換

if let s = userDefault.valueForKey("wordstack"){ 
    var wordStack: [String] = [] 
    for i in s as! NSArray { 
     print(i) 
     wordStack.append(String(i)) 
     print(wordStack) 
    } 
} 

與

wordStack = userDefault.objectForKey("wordstack") 

由於存在空數組wordStack的默認值不能nil並且是類型安全的。

注意：除非您確實需要KVC方法，否則請始終使用objectForKey而不是valueForKey。