Ios StackView UIKit间距似乎非常小的编程式编程

我正在努力复习我的UIKit，但我想不明白为什么在try 在其中添加一些自定义视图时我的堆栈视图间距如此小.我在过go 的一些项目中try 过这种堆栈视图大小，但它们并不一样，这意味着在我的其他项目中，堆栈视图间距显示预期的间距为10，与之相反，当我在下面的代码上设置10间距时，几乎没有任何间距.

class ViewController: UIViewController {
    
    private lazy var vStackView: UIStackView = {
        let stack = UIStackView(arrangedSubviews: [customButtonOne, customButtonTwo])
        stack.translatesAutoresizingMaskIntoConstraints = false
        stack.axis = .vertical
        stack.distribution = .fill
        stack.spacing = 10
        return stack
    }()
        
    private lazy var customButtonOne: CustomView = {
        let button = CustomView()
        return button
    }()
    
    private lazy var customButtonTwo: CustomView = {
        let button = CustomView()
        button.buttonView.setTitle("This is button two", for: .normal)
        return button
    }()
    
    init() {
        super.init(nibName: nil, bundle: nil)
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()
        configure()
    }
    
    func configure() {
        view.addSubview(vStackView)


        NSLayoutConstraint.activate([
            vStackView.centerXAnchor.constraint(equalTo: view.centerXAnchor),
            vStackView.centerYAnchor.constraint(equalTo: view.centerYAnchor),
        ])
    }
}

这就是自定义按钮视图内部的内容:

class CustomView: UIView {
    lazy var buttonView: UIButton = {
        let button: UIButton = UIButton()
        button.translatesAutoresizingMaskIntoConstraints = false
        button.backgroundColor = .systemBlue
        button.setTitle("Hello World", for: .normal)
        button.layer.cornerRadius = 8
        //button.configuration = buttonConfig
        return button
    }()
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        translatesAutoresizingMaskIntoConstraints = false
        addSubview(buttonView)
        setupView()
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    func setupView() {
        NSLayoutConstraint.activate([
            buttonView.centerXAnchor.constraint(equalTo: centerXAnchor),
            buttonView.centerYAnchor.constraint(equalTo: centerYAnchor)
        ])
    }
}