单击时为iOS滚动视图中的按钮添加边框并从其他按钮中删除边框

Question

我在 iOS 的水平滚动视图中添加了按钮。

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

     func setUpScrollView() {
        let buttonPadding:CGFloat = 10
        var xOffset:CGFloat = 10

        for i in 0 ... 10 {
            let button = UIButton()
            button.tag = i
            button.backgroundColor = UIColor.red
            button.setTitle("\(i)", for: .normal)

            if(button.tag==currentTag){
           button.addTarget(self, action: #selector(btnTouchUnselect), for: UIControlEvents.touchUpInside)
            }
            else{

                     button.addTarget(self, action: #selector(btnTouch), for: UIControlEvents.touchUpInside)
            }
            button.frame = CGRect(x: xOffset, y: CGFloat(buttonPadding), width: 70, height: 30)

            xOffset = xOffset + CGFloat(buttonPadding) + button.frame.size.width;
            scrollView.addSubview(button)
        }

        scrollView.contentSize = CGSize(width: xOffset, height: scrollView.frame.height)
    }

    @objc func btnTouch(button:UIButton){
        print("tap touch",button.tag)
            button.layer.borderColor = UIColor.black.cgColor
            button.layer.borderWidth = 1.0
        currentTag = button.tag

    }

    @objc func  btnTouchUnselect(button:UIButton){
        button.layer.borderColor = UIColor.white.cgColor
        button.layer.borderWidth = 1.0

    }

}

我希望一个按钮在用户单击它时获得不同的边框颜色，而其他按钮保持黑色。但是，当我使用此代码时，它会将所有单击的按钮边框变为黑色，并且不会将单击的按钮变为白色。

目标示例：-假设我有 10 个按钮，我希望在单击按钮 1 时，其边框变为白色，其他按钮保持黑色；如果单击按钮 2，则包括按钮 1 在内的所有按钮的边框都会再次变为黑色，只有按钮 2 的边框会变为白色。

我需要一些指导来实现这一目标。

Answer 1

试试这个代码

var allButtons = [UIButton]() 

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

 func setUpScrollView() {
    let buttonPadding:CGFloat = 10
    var xOffset:CGFloat = 10

    for i in 0 ... 10 {
        let button = UIButton()
        button.tag = i
        button.backgroundColor = UIColor.red
        button.layer.borderWidth = 1.0
        button.setTitle("\(i)", for: .normal)
        button.addTarget(self, action: #selector(didTap), for: UIControlEvents.touchUpInside)
        button.frame = CGRect(x: xOffset, y: CGFloat(buttonPadding), width: 70, height: 30)

        xOffset = xOffset + CGFloat(buttonPadding) + button.frame.size.width;
        scrollView.addSubview(button)
        allButtons.append(button)
    }

    scrollView.contentSize = CGSize(width: xOffset, height: scrollView.frame.height)
}

@objc func didTap(button: UIButton) {
    print("tap touch",button.tag)

    allButtons.forEach { inButton in 
         if inButton == button {
            button.layer.borderColor = UIColor.black.cgColor
         } else {
            button.layer.borderColor = UIColor.white.cgColor
         }
    }
    currentTag = button.tag
}

Answer 2

我认为问题在于您的按钮只能在 setScrollView 中访问。 所以当一个按钮被点击时，在@Anton 的回答中，只有被点击的按钮在didTap 函数中是已知的。

我认为一个更好的主意是创建一个UIButtons 的数组， 在setScrollView 发起他们， 然后使用@Anton didTap 函数

class yourClass {

var buttons : [UIButton] = Array(repeatElement(UIButton(), count: 10))

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

func setUpScrollView() {
        let buttonPadding:CGFloat = 10
        var xOffset:CGFloat = 10

        for i in 0...9 {
            buttons[i].tag = i
            buttons[i].backgroundColor = UIColor.red
            buttons[i].setTitle("\(i)", for: .normal)

         //Other functionality that you had set here before...
    }

@objc func didTap(clickedButton: UIButton) {

    for eachButton in self.buttons { 
         if eachButton.tag == clickedButton.tag {
            eachButton.layer.borderColor = UIColor.white.cgColor
         } else {
            eachButton.layer.borderColor = UIColor.balck.cgColor
         }
    }
    currentTag = clickedButton.tag
}


}