AnnotationView中的UIButton -如何保留图标和按钮

// 创建自定义的AnnotationView
class CustomAnnotationView: MKAnnotationView {
    var button: UIButton!
    
    override init(annotation: MKAnnotation?, reuseIdentifier: String?) {
        super.init(annotation: annotation, reuseIdentifier: reuseIdentifier)
        
        // 创建UIButton并设置图标和样式
        button = UIButton(type: .custom)
        button.setImage(UIImage(named: "icon"), for: .normal)
        button.setTitle("按钮", for: .normal)
        button.setTitleColor(.black, for: .normal)
        button.frame = CGRect(x: 0, y: 0, width: 50, height: 50)
        
        // 将UIButton添加到AnnotationView中
        addSubview(button)
        
        // 为UIButton添加点击事件处理函数
        button.addTarget(self, action: #selector(buttonTapped), for: .touchUpInside)
    }
    
    @objc func buttonTapped() {
        // 处理按钮点击事件
        print("按钮被点击了")
    }
    
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}

// 在MapView的代理方法中使用自定义的AnnotationView
func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView? {
    if annotation is MKUserLocation {
        return nil
    }
    
    let reuseIdentifier = "CustomAnnotation"
    var annotationView = mapView.dequeueReusableAnnotationView(withIdentifier: reuseIdentifier)
    
    if annotationView == nil {
        annotationView = CustomAnnotationView(annotation: annotation, reuseIdentifier: reuseIdentifier)
    } else {
        annotationView?.annotation = annotation
    }
    
    return annotationView
}