Swift 1.2 重新声明 Objective-C 方法

Question

我刚刚从 swift 1.1 更新到 swift 1.2 并得到编译器错误:

Method 'setVacation' redeclares Objective-C method 'setVacation:'

这里是一些代码:

var vacation : Vacation?  
func setVacation(_vacation : Vacation)
{...}

但我需要调用setVacation

有什么解决办法的建议吗？

Answer 1

这是由 Xcode 6.3beta 发行说明中所述的更改引起的:

Swift now detects discrepancies between overloading and overriding in the Swift type system and the effective behavior seen via the Objective-C runtime. (18391046, 18383574) For example, the following conflict between the Objective-C setter for “property” in a class and the method “setProperty” in its extension is now diagnosed:

 class A : NSObject {
     var property: String = "Hello" // note: Objective-C method 'setProperty:’
                                    // previously declared by setter for
                                    // 'property’ here
 }
 extension A {
     func setProperty(str: String) { } // error: method ‘setProperty’
                                       // redeclares Objective-C method
                                       //'setProperty:’
 }

要解决这个问题，您需要使所有方法签名都是唯一的(因为 Objective-C 不提供方法重载)

或者如果您只需要 Swift 类，则不要继承 NSObject。