在 Segue 视图上的导航栏添加按钮

Question

您能告诉我如何向模态视图添加按钮吗？我希望它是这样的：

我尝试了navigationItem方法，但它似乎不起作用。

navigationItem.rightBarButtonItem = UIBarButtonItem(barButtonSystemItem: .add, target: self, action: #selector(addNewBDay))

我根本不使用故事板，所以我以这种方式呈现模态视图

let openNextScreen = UIButton()

openNextScreen.addTarget(self, action: #selector(presentModal()), for: .touchUpInside)

@objc func presentModal() {
   let secondScreen = SecondViewController()
   self.navigationController?.present(secondScreen, animated: true)
   print("DEBUG: presentation working")
}

Answer 1

这个问题从一开始就说错了。不存在“Segue View”这样的东西，它是 View 的模态呈现。 标准的 navigationItem 方法不适用于模式呈现。因此，添加这样的按钮的唯一方法是使用 UIButton 手动：

let addButton = UIButton()
let cancelButton = UIButton()

override func viewDidLoad() {
   super.viewDidLoad()
   view.backgroundColor = .white
        
   view.addSubview(addButton)
   addButton.setTitle("Add", for: .normal)
   addButton.titleLabel?.font = .systemFont(ofSize: 17, weight: .semibold)
   addButton.setTitleColor(.systemOrange, for: .normal)
   addButton.snp.makeConstraints { make in
      make.top.equalToSuperview().inset(10)
      make.right.equalToSuperview().inset(15)
      }
        
   view.addSubview(cancelButton)
   cancelButton.setTitle("Cancel", for: .normal)
   cancelButton.titleLabel?.font = .systemFont(ofSize: 17, weight: .semibold)
   cancelButton.setTitleColor(.systemOrange, for: .normal)
   cancelButton.snp.makeConstraints { make in
      make.top.equalToSuperview().inset(10)
      make.left.equalToSuperview().inset(15)
   }