快速更改段开关上的段控制标题颜色

Question

我有一个视图控制器，在它上面我有段控制，我在滑动手势上切换段，现在我希望当我切换段时，当前段标题颜色应该变成白色，剩余颜色应该变成灰色，我已经搜索过了但是我得到了背景颜色更改的结果，如何在段之间切换时更改段控制标题颜色？这是我的滑动段代码，

 let titleTextAttributes = [NSAttributedString.Key.foregroundColor: UIColor.red]
    segmentControl.setTitleTextAttributes(titleTextAttributes, for: .selected)
    segmentControl.fallBackToPreIOS13Layout(using: UIColor.clear)
    let swipeRight = UISwipeGestureRecognizer(target: self, action: #selector(self.swipedRight))
    swipeRight.direction = UISwipeGestureRecognizer.Direction.right
    self.activeView.addGestureRecognizer(swipeRight)

    let swipeLeft = UISwipeGestureRecognizer(target: self, action: #selector(self.swipedLeft))
    swipeLeft.direction = UISwipeGestureRecognizer.Direction.left
    self.closedView.addGestureRecognizer(swipeLeft)

 @objc func swipedRight(){
    segmentControl.selectedSegmentIndex = 0
    self.activeView.isHidden = false
    self.closedView.isHidden = true
    let titleTextAttributes = [NSAttributedString.Key.foregroundColor: UIColor.white]
    segmentControl.setTitleTextAttributes(titleTextAttributes, for: .selected)
    let titleText = [NSAttributedString.Key.foregroundColor: UIColor.gray]
    segmentControl.setTitleTextAttributes(titleText, for: .disabled)

    getActiveQuestionAPI()
}

@objc func swipedLeft(){
    segmentControl.selectedSegmentIndex = 1
    self.activeView.isHidden = true
    self.closedView.isHidden = false
    let titleTextAttributes = [NSAttributedString.Key.foregroundColor: UIColor.white]
    segmentControl.setTitleTextAttributes(titleTextAttributes, for: .selected)
    let titleText = [NSAttributedString.Key.foregroundColor: UIColor.gray]
    segmentControl.setTitleTextAttributes(titleText, for: .disabled)

    getCloseQuestionAPI()
}

Answer 1

要检查段控制值何时更改，您可以使用addTarget 方法，如下所示。

segmentControl.addTarget(self, action: #selector(onSegmentedControlValueChanged(_:)), for: .valueChanged)

然后只需像以前的方法那样实现onSegmentedControlValueChanged：

@objc func onSegmentedControlValueChanged(_ sender: UISegmentedControl) {
  // Do something when segment control value changes
}

要更改段控件的标题文本，您实际上不必检查值何时更改，只需通过以下代码 sn-p 即可实现：

let titleTextAttributesForSelected = [NSAttributedString.Key.foregroundColor: UIColor.white]
let titleTextAttributesForNormal = [NSAttributedString.Key.foregroundColor: UIColor.black]
segmentControll.setTitleTextAttributes(titleTextAttributesForSelected, for: .selected)
segmentControll.setTitleTextAttributes(titleTextAttributesForNormal, for: .normal)

这就是为不同状态更改段控件标题颜色所需的全部内容。