iOS navigationItem.rightBarButtonItem 没有响应其选择器

Question

我有一个从A继承的超类A和一个子类B。我想介绍B。当在类 A 中添加 navigationItem.rightBarButtonItem 时，选择器没有响应其选择器。

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

我认为由于某种原因，当barButtonItem初始化时，它的目标self可能无法完成启动。以这种方式执行：

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