xcode 如何修复“'@IBInspectable' 属性对无法在 Objective-C 中表示的属性毫无意义”警告
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How to fix "'@IBInspectable' attribute is meaningless on a property that cannot be represented in Objective-C" warning
提问by Adrian
In Xcode 9 and Swift 4 I always get this warning for some IBInspectableproperties:
在 Xcode 9 和 Swift 4 中，对于某些IBInspectable属性，我总是收到此警告：
@IBDesignable public class CircularIndicator: UIView {
// this has a warning
@IBInspectable var backgroundIndicatorLineWidth: CGFloat? { // <-- warning here
didSet {
backgroundIndicator.lineWidth = backgroundIndicatorLineWidth!
}
}
// this doesn't have a warning
@IBInspectable var topIndicatorFillColor: UIColor? {
didSet {
topIndicator.fillColor = topIndicatorFillColor?.cgColor
}
}
}
Is there a way to get rid of it ?
有没有办法摆脱它？
回答by dfd
Maybe.
也许。
The exact error(not warning) I got when doing a copy/paste of class CircularIndicator: UIViewis:
我在复制/粘贴类时得到的确切错误（不是警告）CircularIndicator: UIView是：
Property cannot be marked @IBInspectable because its type cannot be represented in Objective-C
属性不能被标记为@IBInspectable 因为它的类型不能在 Objective-C 中表示
I resolved it by making this change:
我通过进行此更改解决了它：
@IBInspectable var backgroundIndicatorLineWidth: CGFloat? { // <-- warning here
didSet {
backgroundIndicator.lineWidth = backgroundIndicatorLineWidth!
}
}
To:
到：
@IBInspectable var backgroundIndicatorLineWidth: CGFloat = 0.0 {
didSet {
backgroundIndicator.lineWidth = backgroundIndicatorLineWidth!
}
}
Of course, backgroundIndicatoris undefined in my project.
当然，backgroundIndicator在我的项目中是未定义的。
But if you are coding against didSet, it looks like you just need to define a default value instead of making backgroundIndicatorLineWidthoptional.
但是，如果您针对 进行编码didSet，则看起来您只需要定义一个默认值而不是使其成为backgroundIndicatorLineWidth可选值。
回答by Aaban Tariq Murtaza
Below two points might helps you
以下两点或许能帮到你
As there is no concept of optional in objective c, So optional IBInspectable produces this error. I removed the optional and provided a default value.
If you are using some enumerations types, then write @objc before that enum to remove this error.
由于目标 c 中没有可选的概念，因此可选的 IBInspectable 会产生此错误。我删除了可选并提供了默认值。
如果您正在使用某些枚举类型，则在该枚举之前写入 @objc 以消除此错误。
回答by Shakeel Ahmed
Swift - 5
斯威夫特 - 5
//Change this with below
@IBInspectable public var shadowPathRect: CGRect!{
didSet {
if shadowPathRect != oldValue {
setNeedsDisplay()
}
}
}
To
到
@IBInspectable public var shadowPathRect: CGRect = CGRect(x:0, y:0, width:0, height:0) {
didSet {
if shadowPathRect != oldValue {
setNeedsDisplay()
}
}
}
