Swift - 如何隐藏标签，然后在按下按钮后使其永远显示？

Question

我试图让标签开始隐藏，然后在按下按钮后让标签永远显示，即使在您注销/重新启动应用程序后也是如此。现在，它在我单击按钮后显示，但在我注销/重新启动后变为隐藏。这是我的代码:

override func awakeFromNib() {
    super.awakeFromNib()
    // Initialization code
    hidePercent()
}

var didTapOptionsButtonForCell: ((YourPollsCell) -> Void)?

override func setSelected(_ selected: Bool, animated: Bool) {
    super.setSelected(selected, animated: animated)

    // Configure the view for the selected state

    let percentColor = UIColor(red: 115/255, green: 21/255, blue: 54/255, alpha: 1.0).cgColor
    pollText1Percent.layer.borderColor = percentColor
    pollText1Percent.layer.borderWidth = 2
    pollText2Percent.layer.borderColor = percentColor
    pollText2Percent.layer.borderWidth = 2
}

func hidePercent() {
    pollText1Percent.isHidden = true
    pollText2Percent.isHidden = true
}

@IBAction func reportButtonTapped(_ sender: UIButton) {
    didTapOptionsButtonForCell?(self)
}

@IBAction func pollText1ButtonTapped(_ sender: UIButton) {
    delegate?.didTapVoteButton(sender, pollNum: 1, on: self)

    pollText1Percent.isHidden = false
    pollText2Percent.isHidden = false
}

@IBAction func pollText2ButtonTapped(_ sender: UIButton) {
    delegate?.didTapVoteButton(sender, pollNum: 2, on: self)

    pollText1Percent.isHidden = false
    pollText2Percent.isHidden = false
}

Answer 1

点击按钮时，您可以向 UserDefaults 添加一个值。

UserDefaults.standard.set(value: true, forKey: "specialButtonWasTapped")

然后在应用程序启动时在 Controller 中检查此值并设置 isHidden 属性。

if let wasTapped = UserDefaults.standard.value(forKey: "specialButtonWasTapped") {
    specialLabel.isHidden = !wasTapped    // false
}
else {
    specialLabel.isHidden = true
}

或者清理这个想法

UserDefaults.standard.set(value: false, forKey: "labelShouldBeHidden")

然后你可以使用 nil 合并运算符设置 isHidden 属性

specialLabel.isHidden = (UserDefaults.standard.value(forKey: "labelShouldBeHidden") as? Bool) ?? true