旋转按钮titleLabel文本

import UIKit

class ViewController: UIViewController {

    var button: UIButton!

    override func viewDidLoad() {
        super.viewDidLoad()

        // 创建按钮
        button = UIButton(type: .custom)
        button.frame = CGRect(x: 100, y: 100, width: 200, height: 50)
        button.setTitle("旋转按钮", for: .normal)
        button.setTitleColor(.black, for: .normal)
        button.addTarget(self, action: #selector(buttonTapped), for: .touchUpInside)
        view.addSubview(button)
    }

    @objc func buttonTapped() {
        // 更新按钮titleLabel的文本
        button.titleLabel?.text = "加载中..."
        
        // 创建旋转动画
        let rotationAnimation = CABasicAnimation(keyPath: "transform.rotation.z")
        rotationAnimation.toValue = NSNumber(value: Double.pi * 2) // 旋转一周
        rotationAnimation.duration = 1.0
        rotationAnimation.repeatCount = .infinity
        button.layer.add(rotationAnimation, forKey: "rotationAnimation")
    }
}