Question

我有一个带有IBInspectable颜色属性的自定义UIView类：

class MyParent: UIView {
    // use CGColor for setting background (a gradient), and IBInspectable UIColor to choose color in Interface Builder
    var color1: CGColor = UIColor(red: 100.0/255.0, green: 130.0/255.0, blue: 230.0/255.0, alpha: 1.0).CGColor
    var color2: CGColort = UIColor(red: 200.0/255.0, green: 30.0/255.0, blue: 30.0/255.0, alpha: 1.0).CGColor
    @IBInspectable var UIcolor1: UIColor = UIColor(red: 100.0/255.0, green: 130.0/255.0, blue: 230.0/255.0, alpha: 1.0) {
        didSet {
            color1 = UIcolor1.cgColor
        }
    }

    // INIT: Set gradient with color1/2 for the background of MyParent view
    override init(frame: CGRect) {
        super.init(frame: frame);
        var gradient = CAGradientLayer()
        gradient.frame = bounds
        gradient.colors = [color1, color2]
        layer.insertSublayer(gradient, at: 0)
    }
}

更新以进行澄清：这样做是为了能够在Interface Builder中选择一种颜色（仅适用于UIColor），但是由于视图的背景是渐变，它需要转换为CGColor。因此，didSet完成了这项工作，并且在IB中选择了UIColor之后，背景分别发生了变化。

现在我想拥有另一个自定义UIView，它是MyParent的子类，我想设置另一个默认的UIcolor1，但出现错误：

class MySubclass: MyParent {
    // override UIcolor1
    override var UIcolor1: UIColor = UIColor.blue

    // ...
}

以下错误：

Cannot override the stored property 'UIcolor1'

我该如何工作？

Answer 1

如果您不想在初始设置颜色，我认为您可以在这里做到最好

class MySubclass: MyParent {
// override UIcolor1
  override var UIcolor1: UIColor {
      get {
          return .blue
      }
      set {
          color1 = newValue.cgColor
      }
   }
// ...
}

代码修改后

我认为这种子类化视图的用法是不必要的。这是工作代码

@IBDesignable
class MyParent: UIView {
    // use CGColor for setting background, and IBInspectable UIColor to choose color in Interface Builder
    var color1: UIColor = UIColor.blue {
        didSet {
            gradientLayer.colors = [color1.cgColor, color2]
        }
    }

   var color2: CGColor = UIColor.green.cgColor

   @IBInspectable var inspectableColor1: UIColor {
       get {
           return color1
       }
       set {
           color1 = newValue
       }
   }

   private var gradientLayer = CAGradientLayer()
   // INIT: Set color1 for the background of MyParent view
   // ...
   override init(frame: CGRect) {
      super.init(frame: frame)
      setupLayer()
   }

   required init?(coder aDecoder: NSCoder) {
      super.init(coder: aDecoder)
      setupLayer()
  }

  func setupLayer() {
      gradientLayer.frame = bounds
      gradientLayer.colors = [color1.cgColor, color2]
      layer.insertSublayer(gradientLayer, at: 0)
  }
}

具有IBInspectable颜色属性的子类-无法覆盖

1 个答案: