收藏查看收藏按鈕按下迅速

Question

我有一個收藏視圖，它需要存儲哪個按鈕被按下。這就好比一個測驗，他們有選項A，B，C，D的問題是，它會與此代碼選擇項：

extension QuestionCell { 
func configure(with model: Question) { 
    factLabel.text = model.fact 
    questionLabel.text = model.question 
    revenueLabel.text = model.revenue 
    let views = answersStack.arrangedSubviews 
    for view in views { 
     view.removeFromSuperview() 
    } 
    for (id, answer) in model.answers { 
     print(index) 
     let answerLabel = UILabel() 
     answerLabel.text = answer 

     answersStack.addArrangedSubview(answerLabel) 

     let answerButton = UIButton() 
     answerButton.tag = index 
     let imageNormal = UIImage(named: "circle_empty") 
     answerButton.setImage(imageNormal, for: .normal) 
     let imageSelected = UIImage(named: "circle_filled") 
     answerButton.setImage(imageSelected, for: .selected) 
     answerButton.setTitleColor(.black, for: .normal) 
     answerButton.addTarget(self, action: #selector(answerPressed(_:)), for: .touchUpInside) 
     answersStack.addArrangedSubview(answerButton) 

    } 
} 

不過，如果你刷幾次，然後回來這個問題的形象會再次變成白色。我該如何解決這個問題。我還附上了屏幕的外觀。

This is how it looks like

〜感謝

Answer 1

你可以一個答案類這樣的解決這個問題。如果你是新的班，我要指出，你不會想寫內其他的類定義的代碼（如您的ViewController類）。

class Answer{ 
    var wasSelected = false 
    var text : String 

    init(text : String) { 
     self.text = text 
    } 

} 
class ButtonWithAnswer : UIButton{ 
    var answer : Answer? 
} 

但現在你model.answers會這個樣子，並將於[String : Answer]類型：

model.answers = ["id1" : Answer(text : "answer 1"), "id2" : Answer(text: "answer 2"), "id3":Answer(text: "answer 3")] 

的想法是，而不是有model.answers包含字符串，它們包含我們由被叫應答，可保持文本的軌道新的自定義類型對於答案（這是一個名爲String類型的文本的屬性）以及它是否是s當選（這是一個名爲wasSelected的屬性Bool）。您的for循環現在看起來像這樣：

for (id, answer) in model.answers { 
    let answerLabel = UILabel() 
    answerLabel.text = answer.text //this comes from our new class definition 

    answersStack.addArrangedSubview(answerLabel) 
    //Change this to our new custom button subclass 
    let answerButton = ButtonWithAnswer() 
    //this line straight up won't work since you got rid of index 
    //answerButton.tag = index 

    //use this instead 
    answerButton.answer = answer 
    let imageNormal = UIImage(named: "circle_empty") 
    answerButton.setImage(imageNormal, for: .normal) 
    let imageSelected = UIImage(named: "circle_filled") 
    answerButton.setImage(imageSelected, for: .selected) 

    //make it so that any answers that were previously selected are now selected when the view reloads 
    answerButton.isSelected = answer.wasSelected 


    answerButton.setTitleColor(.black, for: .normal) 
    answerButton.addTarget(self, action: #selector(answerPressed(_:)), for: .touchUpInside) 
    answersStack.addArrangedSubview(answerButton) 


} 

這裏有一個最後一部分。當我們點擊與該答案相對應的按鈕時，我們需要確保我們的答案被選中。所以在回答我們應該做這樣的事情。

func answerPressed(_ sender : UIButton){ 
    let answerForButton = (sender as! ButtonWithAnswer).answer! 
    answerForButton.wasSelected = true 


} 

這應該關於掩蓋它。如果這看起來像是一個全新的東西，那麼在你潛入之前，你應該在Swift中查找關於Swift中的類，對象和init方法的教程，或者親自向程序員請求幫助。但我儘可能地解釋了這一點，而沒有真正親自到場給你一個完整的演練。