Swift UIButton显示和淡入子视图:在‘OKButtonPressed]上崩溃:发送了无法识别的选择器

@objc func okButtonPressed() {
    // 实现按钮被按下时的逻辑
}

okButton.addTarget(self, action: #selector(okButtonPressed), for: .touchUpInside)

if let customButton = button as? CustomButton {
    customButton.addTarget(self, action: #selector(customButton.okButtonPressed), for: .touchUpInside)
}

okButton.addTarget(self, action: #selector(okButtonPressed), for: .touchUpInside)

{ [weak self] in
    guard let self = self else { return }
    // 使用 self
}

import UIKit

class ViewController: UIViewController {

    let okButton = UIButton(type: .system)
    let subview = UIView()

    override func viewDidLoad() {
        super.viewDidLoad()
        
        setupButton()
        setupSubview()
    }

    func setupButton() {
        okButton.setTitle("OK", for: .normal)
        okButton.addTarget(self, action: #selector(okButtonPressed), for: .touchUpInside)
        view.addSubview(okButton)
        // 设置按钮布局...
    }

    func setupSubview() {
        subview.backgroundColor = .blue
        view.addSubview(subview)
        subview.alpha = 0 // 初始时透明
        // 设置子视图布局...
    }

    @objc func okButtonPressed() {
        UIView.animate(withDuration: 0.3) {
            self.subview.alpha = 1 // 淡入子视图
        }
    }
}