iOS13 - UIButton 标题颜色仅显示黑色或白色而不是橙色

Question

橙色在具有 iOS14 的 iphoneXR（设备）上显示良好，并且在深色和浅色模式之间保持橙色。但是在带有 iOS13（设备）的 iphone 11 上，标题颜色仅显示为黑色或白色，具体取决于暗/亮模式。 为什么要覆盖橙色？我该怎么做才能让所有设备的标题都保持橙色？

iphone 11 和 iOS13 截图：

iphone XR 与 iOS14.2 截图：

使用 XCode 版本 12

我试过了：

button.setTitleColor(.systemOrange, for: .normal)
button.setTitleColor(.placeholderText, for: .normal) //this led to a grey color on ios14 as expected but black on iOS13
button.setTitleColor(UIColor.orange, for: .normal)
button.setTitleColor(UIColor.customAccent, for: .normal)

extension UIColor {
  static var customAccent: UIColor {
      if #available(iOS 13, *) {
          return UIColor { (traitCollection: UITraitCollection) -> UIColor in
              if traitCollection.userInterfaceStyle == .dark {
                return UIColor(red: 0.8196078431, green: 0.3568627451, blue: 0.2235294118, alpha: 1.0)
              } else {
                  return UIColor(red: 0.8196078431, green: 0.3568627451, blue: 0.2235294118, alpha: 1.0)
              }
          }
      } else {
          return UIColor(red: 0.8196078431, green: 0.3568627451, blue: 0.2235294118, alpha: 1.0)
      }
  }

按钮以编程方式设置：

    let attributedText = [NSAttributedString.Key.font: UIFont(name: "Poppins-Regular", size: 15.0)!]
    button1.layer.borderColor = #colorLiteral(red: 0.8196078431, green: 0.3568627451, blue: 0.2235294118, alpha: 1)
    button1.layer.borderWidth = 1.0
    button1.setTitleColor(.placeholderText, for: .normal)
    button1.backgroundColor = UIColor.white
    button1.layer.cornerRadius = 32
    button1.clipsToBounds = true
    button1.setAttributedTitle(NSAttributedString(string: "PLACEHOLDER TEXT", attributes: attributedText), for: .normal)
    button1.translatesAutoresizingMaskIntoConstraints = false
    self.addSubview(button1)
    self.addConstraint(NSLayoutConstraint(item: button1, attribute: NSLayoutConstraint.Attribute.height, relatedBy: NSLayoutConstraint.Relation.equal, toItem: nil, attribute: NSLayoutConstraint.Attribute.notAnAttribute, multiplier: 0, constant: 64))
    self.addConstraint(NSLayoutConstraint(item: button1, attribute: NSLayoutConstraint.Attribute.leading, relatedBy: NSLayoutConstraint.Relation.equal, toItem: self, attribute: NSLayoutConstraint.Attribute.leading, multiplier: 1, constant: 45))
    self.addConstraint(NSLayoutConstraint(item: self, attribute: NSLayoutConstraint.Attribute.trailing, relatedBy: NSLayoutConstraint.Relation.equal, toItem: button1, attribute: NSLayoutConstraint.Attribute.trailing, multiplier: 1, constant: 45))
    self.addConstraint(NSLayoutConstraint(item: button1, attribute: NSLayoutConstraint.Attribute.centerX, relatedBy: NSLayoutConstraint.Relation.equal, toItem: self, attribute: NSLayoutConstraint.Attribute.centerX, multiplier: 1, constant: 0))
    self.addConstraint(NSLayoutConstraint(item: button1, attribute: NSLayoutConstraint.Attribute.top, relatedBy: NSLayoutConstraint.Relation.equal, toItem: reScanButton!, attribute: NSLayoutConstraint.Attribute.bottom, multiplier: 1, constant: 15))

Answer 1

我认为这是因为您为同一状态设置了两种不同的颜色。

尝试改变按钮的状态。

button.setTitleColor(UIColor.orange, for: .normal)
button.setTitleColor(UIColor.customAccent, for: .touchUpInside)

您可以在此处阅读文档：https://developer.apple.com/documentation/uikit/uicontrol/state

Answer 2

如果您有UILabel，您通常不想混合属性，因为您可能会得到奇怪/混合的结果，正如您所看到的：

attributedText
vs
text、font、textColor、texAlignment 或 lineBreakMode

UITextView 和 UIButton 也是如此（引擎盖下有一个 UILabel）。

所以继续使用NSAttributedString，例如：

let state: UIControl.State = .normal
guard let currentAttributedTitle = button.attributedTitle(for: state) else { return }
let attributedTitle = NSMutableAttributedString(attributedString: currentAttributedTitle)
attributedTitle.setAttributes([.foregroundColor: color], range: NSRange(location: 0, length: attributedTitle.length))
button.setAttributedTitle(attributedTitle, for: state)