Swift 4.1 - 子类UIImage

Question

我得到的Overriding non-@objc declarations from extensions is not supported错误,当升级到4.1雨燕后子类UIImage的自定义的init

class Foo: UIImage {

    init(bar: String) { }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    // Overriding non-@objc declarations from extensions is not supported
    required convenience init(imageLiteralResourceName name: String) {
        fatalError("init(imageLiteralResourceName:) has not been implemented")
    }
}

谢谢你的帮助

Answer 1

extension UIImage {

    /// Creates an instance initialized with the given resource name.
    ///
    /// Do not call this initializer directly. Instead, initialize a variable or
    /// constant using an image literal.
    required public convenience init(imageLiteralResourceName name: String)
}

这个 init 方法是在UIImage类的扩展中声明的。

该错误几乎是说，如果在扩展中声明了一个函数，则不能以这种方式覆盖它

class Foo: UIImage {

}

extension Foo {
    convenience init(bar :String) {
        self.init()
    }
}

var temp = Foo(bar: "Hello")

您可以尝试以这种方式实现所需的结果。