increment/decrement 带有两个按钮的标签的值

Question

作为 swift 的新手意味着我在使用两个按钮来递增 label.I 的值时遇到问题，因为递增按钮有效但递减按钮不起作用。我想存储在标签内的值减少了，但标签没有更新。这是代码，谢谢 PS：所有这些 isEnabled = true 或 false 只是为了禁用按钮能够创建从 0 到 5 的范围

class ViewController: UIViewController {
var incDec = 0;
@IBOutlet weak var countLbl: UILabel!
@IBOutlet weak var decBtn: UIButton!
@IBOutlet weak var incBtn: UIButton!

override func viewDidLoad() {
    super.viewDidLoad()
    
    
}
@IBAction func tapDec(_ sender: Any) {
    if(incDec >= -1){
            incDec -= 1;
            self.countLbl.text = "\(incDec)"
            decBtn.isEnabled = true
        }
        else{
            self.countLbl.text = "\(incDec)"
            decBtn.isEnabled = false
            incBtn.isEnabled = true
        }
}


@IBAction func tapInc(_ sender: Any) {

    if(incDecVal < 5){
        incDec += 1;
        self.countLbl.text = "\(incDec)"
        incBtn.isEnabled = true
    }
    else{
        self.countLbl.text = "\(incDec)"
        incBtn.isEnabled = false
        decBtn.isEnabled = true
    }
    
}

}

Answer 1

您必须修改启用和禁用按钮的逻辑。这是代码。

class ViewController: UIViewController {
    var incDecVal = 0;
    @IBOutlet weak var countLbl: UILabel!
    @IBOutlet weak var decBtn: UIButton!
    @IBOutlet weak var incBtn: UIButton!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        countLbl.text = "\(incDecVal)"
    }

    @IBAction func tapDec(_ sender: Any) {
        if(incDecVal > 0){
            incDecVal = incDecVal - 1;
        }
        
        decBtn.isEnabled = incDecVal == 0 ? false : true
        incBtn.isEnabled = true
        self.countLbl.text = "\(incDecVal)"
    }
    
    @IBAction func tapInc(_ sender: Any) {
        
        if(incDecVal <= 5) {
            incDecVal = incDecVal + 1;
        }
        
        incBtn.isEnabled = incDecVal == 5 ? false : true
        decBtn.isEnabled = true
        self.countLbl.text = "\(incDecVal)"
    }
}

increment/decrement 带有两个按钮的标签的值

increment/decrement the value of a label with two buttons

swift