Swift：#selector無法識別？

Question

我是新來的迅速和我試圖從斯坦福大學的演講重現此代碼：

@IBOutlet weak var faceView: FaceView! { 
     didSet { 
      faceView.addGestureRecognizer(UIPinchGestureRecognizer(target: faceView, action: #selector(FaceView.changeScale(_:)))) 
    } 
} 

然而，它給我的錯誤：

'expected expression in list of expressions'.

錯誤指向#selector。 我做錯了什麼？

Answer 1

如何：

@IBOutlet weak var faceView: FaceView! { 
     didSet { 
     faceView.addGestureRecognizer(UIPinchGestureRecognizer(target: faceView, action: Selector(FaceView.changeScale))) 
    } 
}