Swift 2,使用Objective-C选择器'setOn:'的方法'setOn'与使用相同Objective-C选择器的'on'的setter冲突

Question

Swift 2,我有一个继承自objc的UIView的类,它有'on'变量,以及相关方法'setOn:animated'和'setOn:',如下所示:

public class AView: UIView {
var on: Bool = false

public func setOn(on: Bool, animated: Bool) {
    self.on = on
    // do something more about animating
}

public func setOn(on: Bool) {
    setOn(on, animated: false)
}

我收到一条错误消息: method 'setOn' with Objective-C selector 'setOn:' conflicts with setter for 'on' with the same Objective-C selector

我认为willSet或didSet不是解决方案,因为setOn:animated:即使我添加了一些保护条件,也会被调用两次:

var on: Bool = false {
    willSet {
        if self.on != newValue {
            setOn(self.on, animated: false)
        }
    }
}
....
....
let a = AView()
a.setOn(true, animated: true) // setOn:animated: is called twice

有没有更改变量名称和方法名称的解决方案？

---

解决方法:我的解决方案是添加额外的内部变量并使用computed属性公开它.我不喜欢添加额外的变量,肯定会有更好的解决方案.

private var isOn: Bool = false
var on: Bool {
    set(newOn) {
        setOn(newOn, animated: false)
    }
    get {
        return isOn
    }
}

public func setOn(on: Bool, animated: Bool) {
    self.isOn = on
    // do something ...
}

Answer 1

与编译器错误类似:使用Objective-C选择器的方法与先前使用相同Objective-C选择器的声明冲突,您还可以使用以下方法隐藏Objective-C运行时中的属性@nonobjc:

public class AView: UIView {
    @nonobjc var on: Bool = false

    public func setOn(on: Bool, animated: Bool) {
        self.on = on
        // do something more about animating
    }

    public func setOn(on: Bool) {
        setOn(on, animated: false)
    }
}

这可以防止自动生成冲突的Objective-C setter.