如何返回到在同一個視圖控制器上隨機生成的以前的數據

Question

我是新來編碼，我試圖編碼隨機生成器，顯示隨機引號。我能夠做到這一點。但是我希望能夠回到之前我已經生成的引號，並且無法找到實現它的方法。我沒有xcode顯示。任何幫助將不勝感激

var myQuotes = ["Adversity is The Universe's Way of Directing Us Down a Differnt Path", "Pain is Temporary, Glory is Forever", "As You Think, So Shall You Become", "If You Can Dream It, You Can Achieve It", "Dreaming, Afterall, is a Form of Planning"] 

var randomGeneratedQuotes = Array <String>() 
var currentlyShown : String? 
var randomQuote: String { 
    let randomNumber = Int(arc4random_uniform(UInt32(myQuotes.count))) 
    return myQuotes[randomNumber] 

} 

var previousRandom: String? { 

    if currentlyShown == randomQuote { 
     let previous = randomGeneratedQuotes.index(of: currentlyShown!)! - 1 
     return randomGeneratedQuotes[previous] 
    } 

    return randomGeneratedQuotes.last 
} 




override func viewDidLoad() { 
    super.viewDidLoad() 
    // Do any additional setup after loading the view, typically from a nib. 

    var randomQuote: String { 
     let randomNumber = Int(arc4random_uniform(UInt32(myQuotes.count))) 
     return myQuotes[randomNumber] 

    } 
    quotesLabel.text = randomQuote 

    func storePrevious() { 
     if randomGeneratedQuotes.contains(randomQuote) {return} 
     randomGeneratedQuotes.append(randomQuote) 
} 
} 

//right hand button tapped 

@IBAction func RHSButton(_ sender: Any) { 

    var randomQuote: String { 
     let randomNumber = Int(arc4random_uniform(UInt32(myQuotes.count))) 
     return myQuotes[randomNumber] 


    } 
    quotesLabel.text = randomQuote 

    func storePrevious() { 
     if randomGeneratedQuotes.contains(randomQuote) {return} 
     randomGeneratedQuotes.append(randomQuote) 
    } 

} 

//left hand button tapped 

@IBAction func LHSButton(_ sender: Any) { 


    func pressedBack() { 
     currentlyShown = previousRandom 


    } 

    quotesLabel.text = previousRandom 




} 

}

Answer 1

您可以簡單地創建VAR保留以前的報價。並在用戶按下時返回。或者如果你想在按下後所有的報價來。您可以爲他們保留一個單獨的數組，如var generatedQuotes = Array（）。並在動作上向後遍歷元素。只需將隨機元素附加到數組中或將lastQuote字符串保存在var中即可。

class ViewController: UIViewController { 
    var myQuotes = ["A","b","c"] // your all quotes stored here. 
    var randomGeneratedQuotes = Array<String>() // empty on start 
    var currentlyShown : String? 
    //use this not so random but will generate a random one 
    var randomQuote: String { 
     let randomNumber = Int(arc4random_uniform(UInt32(myQuotes.count))) 
     return myQuotes[randomNumber] 
    } 
    var previousRandom: String? { 
     if currentlyShown == nil { 
      let previous = randomGeneratedQuotes.indexOf(currentlyShown) - 1 
      return randomGeneratedQuotes[previous] 
     } 

     return randomGeneratedQuotes.last 
    } 
    func storePrevious() { 
     if randomGeneratedQuotes.contains(randomQuote) { return } // already has 
      randomGeneratedQuotes.append(randomQuote) 
    } 
    func pressedBack() { 
     currentlyShown = previousRandom 
     print(previous) 

}