Question

Swift 2，我有一个继承自objc的UIView的课程，并且有一个＆＃39; on＆＃39;变量和相关方法＆＃39; setOn：animated＆＃39;和＆＃39; setOn：＆＃39;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，因为即使我添加了一些保护条件，setOn:animated: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

是否有解决方案而不更改变量名称和方法名称？

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。我不想添加额外的变量，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Compiler error: Method with Objective-C selector conflicts with previous declaration with the same Objective-C selector类似，您也可以隐藏属性带有@nonobjc的Objective-C运行时：

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)
    }
}

可防止自动生成冲突的Objective-C setter。

Answer 2

而不是willSet您需要使用didSet

var on: Bool = false
{
    didSet
   {
        if self.on != oldValue
        {
            setOn(self.on, animated: false)
        }
    }
}

Swift 2，方法＆＃39; setOn＆＃39;使用Objective-C选择器＆＃39; setOn：＆＃39;与安装者的冲突与“＃”;使用相同的Objective-C选择器

2 个答案: