在awakeFromNib（）上-错误实例成员“按钮”不能用于类型“ CustomView”

我已经创建了一个自定义UIView作为.xib文件，其中UIView具有一个按钮。我使用以下代码加载UIView。

struct ContentView: View {
    var body: some View {
        CustomViewRepresentable()
    }
}

struct CustomViewRepresentable: UIViewRepresentable {
    typealias UIViewType = CustomView

    func makeUIView(context: UIViewRepresentableContext<CustomViewRepresentable>) -> CustomView {
        let customView = Bundle.main.loadNibNamed("CustomView", owner: nil, options: nil)![0] as! CustomView
        return customView
    }

    func updateUIView(_ uiView: CustomView, context: UIViewRepresentableContext<CustomViewRepresentable>) {
    }
}

自定义视图具有以下代码：

class CustomView: UIView {

    @IBOutlet weak var button: UIButton!

    override init(frame: CGRect) {
        super.init(frame: frame)
    }

    required init?(coder: NSCoder) {
        super.init(coder: coder)
    }

    override class func awakeFromNib() {
        super.awakeFromNib()
        // Error - Instance member 'button' cannot be used on type 'CustomView'
        button.addTarget(self, action: #selector(touchUpInside), for: .touchUpInside)
    }

    @objc func touchUpInside(_ sender: UIButton) {
        print("Button clicked")
    }
}

我已将源代码上传到github。这是链接https://github.com/felixmariaa/AwakeFromNibTest/

这应该可以工作，但我不确定出什么问题了。