iOS navigationItem.rightBarButtonItem 没有响应它的选择器

Question

我有一个继承自 A 的超级 class A 和一个子 classb B。我想展示 B。当在 class A 中添加 navigationItem.rightBarButtonItem 时，选择器未响应其选择器。

class A: UIViewController {

var saveNaviBtn: UIBarButtonItem = UIBarButtonItem(title: "save", style: .done, target: self, action: #selector(save))    

@objc func save() {
    dismiss(animated: true)
}

override func viewDidLoad() {
    super.viewDidLoad()
    self.navigationItem.rightBarButtonItem = saveNaviBtn

}
}
class B: A {

}

Answer 1

我认为出于某种原因，当 barButtonItem 初始化时，它的目标 self 可能没有完成初始化。这样做：

class A: UIViewController {
    var saveNaviBtn: UIBarButtonItem?

    override func viewDidLoad() {
        saveNaviBtn = UIBarButtonItem(title: "save", style: .done, target: self,      action: #selector(save))
        self.navigationItem.rightBarButtonItem = saveNaviBtn
    }
}