Swift 1.2 为什么我不能继承任何 NSCell 的子类？

Question

为什么我不能继承 NSCell 的任何子类？ 我想继承MyButtonCell，即CustomButtonCell: NSButtonCell。意义

class MyCustomButtonCell: MyButtonCell { }

总是给我以下错误：

<unknown>:0: error: declaration has a different @objc name from the declaration it overrides ('initTextCell:' vs. 'initWithTextCell:')
Custom_Controls.MyButtonCell:9:24: note: overridden declaration is here
  @objc @objc override init(textCell aString: String)
                       ^
<unknown>:0: error: declaration has a different @objc name from the declaration it overrides ('initImageCell:' vs. 'initWithImageCell:')
Custom_Controls.MyButtonCell:10:24: note: overridden declaration is here
  @objc @objc override init(imageCell image: NSImage?)
                       ^

重现我的问题的简单步骤：

1. 打开终端

2. 输入：swift（如果你有最新的 Xcode 6.3.1）

3. 当你得到时，

   Welcome to Swift version 1.2. Type :help for assistance.

输入以下内容：

1> import AppKit
2> class Foo : NSCell {}
3> class Bar : Foo {} 

4. 您会收到以下错误：

declaration has a different @objc name from the declaration it overrides ('initTextCell:' vs. 'initWithTextCell:')__lldb_expr_9.Foo:3:24: note: overridden declaration is here @objc @objc override init(textCell aString: String) ^ declaration has a different @objc name from the declaration it overrides ('initImageCell:' vs. 'initWithImageCell:')__lldb_expr_9.Foo:4:24: note: overridden declaration is here @objc @objc override init(imageCell image: NSImage?) ^

为什么？有没有办法解决这个问题？

仅供参考：Swift 1.1 没有这个问题！

Answer 1

看来添加符合NSCoding的init方法可以消除错误：

import AppKit
class Foo : NSCell {
    required init(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
    }
}
class Bar : Foo {}