不能以编程方式dropdown按钮检查按钮标题(代码片段)

我是斯威夫特的新人，我的英语不是很好

问题是我从本教程构建了一个下拉视图

youtube：https://youtu.be/22zu-OTS-3M github：https://github.com/Archetapp/Drop-Down-Menu

他以编程方式创建了一个没有故事板的精彩下拉视图

代码在我的Xcode上运行得非常好

但是当我用按钮检查标题时

我从来没有得到它。

这是我的代码

class ViewController: UIViewController, GMSMapViewDelegate

      override func viewDidLoad() 
      super.viewDidLoad()

      let typeBTN = dropDownBtn()
         self.view.addSubview(typeBTN)
         typeBTN.setTitle("animal", for: .normal)
         typeBTN.dropView.dropDownOptions = ["dog", "cat", "cow", "boy"]


 // ....

protocol dropDownProtocol 
    func dropDownPressed(string: String)


class dropDownBtn: UIButton, dropDownProtocol 

    func dropDownPressed(string: String) 
        self.setTitle(string, for: .normal)
        self.dismissDropDown()
    

    var dropView = dropDownView()
    var height = NSLayoutConstraint()



    override init(frame: CGRect) 
        super.init(frame: frame)
        self.backgroundColor = UIColor.darkGray

        dropView = dropDownView.init(frame: CGRect.init(x: 0, y: 0, width: 0, height: 0))
        dropView.delegate = self
        dropView.translatesAutoresizingMaskIntoConstraints = false
    

    override func didMoveToSuperview() 
        self.superview?.addSubview(dropView)
        self.superview?.bringSubviewToFront(dropView)
        dropView.topAnchor.constraint(equalTo: self.bottomAnchor).isActive = true
        dropView.centerXAnchor.constraint(equalTo: self.centerXAnchor).isActive = true
        dropView.widthAnchor.constraint(equalTo: self.widthAnchor).isActive = true
        height = dropView.heightAnchor.constraint(equalToConstant: 0)
    

    var isOpen = false

    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) 

        if isOpen == false 
            isOpen = true
            NSLayoutConstraint.deactivate([self.height])
            if self.dropView.tableView.contentSize.height > 150 
                self.height.constant = 170
             else 
                self.height.constant = self.dropView.tableView.contentSize.height
            
            NSLayoutConstraint.activate([self.height])
            UIView.animate(withDuration: 0.5, delay: 0, usingSpringWithDamping: 0.5, initialSpringVelocity: 0.5, options: .curveEaseOut, animations: 
                self.dropView.layoutIfNeeded()
                self.dropView.center.y += self.dropView.frame.height / 2
            , completion: nil)

        else dismissDropDown() 
    

    func dismissDropDown() 
        isOpen = false
        NSLayoutConstraint.deactivate([self.height])
        self.height.constant = 0
        NSLayoutConstraint.activate([self.height])
        UIView.animate(withDuration: 0.5, delay: 0, usingSpringWithDamping: 0.5, initialSpringVelocity: 0.5, options: .curveEaseOut, animations: 
            self.dropView.center.y -= self.dropView.frame.height / 2
            self.dropView.layoutIfNeeded()
        , completion: nil)   
    


    required init?(coder aDecoder: NSCoder) 
        fatalError("init(coder:) has not been implemented")
    


class dropDownView: UIView, UITableViewDelegate, UITableViewDataSource  

    var dropDownOptions = [String]()
    var tableView = UITableView()
    var delegate: dropDownProtocol!

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

        tableView.backgroundColor = UIColor.darkGray
        tableView.delegate = self
        tableView.dataSource = self
        self.addSubview(tableView)
        tableView.translatesAutoresizingMaskIntoConstraints = false
        tableView.leftAnchor.constraint(equalTo: self.leftAnchor).isActive = true
        tableView.rightAnchor.constraint(equalTo: self.rightAnchor).isActive = true
        tableView.topAnchor.constraint(equalTo: self.topAnchor).isActive = true
        tableView.bottomAnchor.constraint(equalTo: self.bottomAnchor).isActive = true


    

    required init?(coder aDecoder: NSCoder) 
        fatalError("init(coder:) has not been implemented")
    

    func numberOfSections(in tableView: UITableView) -> Int 
        return 1
    

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int 
       return dropDownOptions.count
    

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell 
        let cell = UITableViewCell()
        cell.textLabel?.text = dropDownOptions[indexPath.row]
        cell.backgroundColor = UIColor.darkGray
        return cell
    

    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) 

        self.delegate.dropDownPressed(string: dropDownOptions[indexPath.row])

        print(dropDownOptions[indexPath.row])

我已经尝试了很多来检查按钮标题何时更改。像这样

 print(typeBTN.currentTitle!)
 print(typeBTN.titleLabel?.text! )
 print(typeBTN.title(for: .normal))
 //I get nothing when i pressed dropdown menu options?

因为我想这样做

if typeBTN.currentTitle == "dog" 
        //show some date at my mapview
    

但是当我点击下拉菜单的“狗”时

它永远不会奏效

有人能帮助我吗？