如何在MKAnnotation上显示核心数据中的多个项目

import MapKit

class CustomAnnotation: NSObject, MKAnnotation {
    var coordinate: CLLocationCoordinate2D
    var title: String?
    var projects: [Project] // 存储多个项目的核心数据
    
    init(coordinate: CLLocationCoordinate2D, title: String?, projects: [Project]) {
        self.coordinate = coordinate
        self.title = title
        self.projects = projects
    }
}

class Project {
    var name: String
    var description: String
    // 其他需要显示的属性
    
    init(name: String, description: String) {
        self.name = name
        self.description = description
    }
}

class MapViewController: UIViewController, MKMapViewDelegate {
    @IBOutlet weak var mapView: MKMapView!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // 设置地图视图的代理
        mapView.delegate = self
        
        // 创建自定义的MKAnnotation对象
        let annotation = CustomAnnotation(coordinate: CLLocationCoordinate2D(latitude: 37.7749, longitude: -122.4194), title: "San Francisco", projects: [
            Project(name: "Project 1", description: "This is project 1"),
            Project(name: "Project 2", description: "This is project 2")
        ])
        
        // 将MKAnnotation对象添加到地图视图中
        mapView.addAnnotation(annotation)
    }
    
    // MKMapViewDelegate代理方法，用于创建和配置MKAnnotationView
    func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView? {
        guard let annotation = annotation as? CustomAnnotation else {
            return nil
        }
        
        let identifier = "CustomAnnotationView"
        var annotationView = mapView.dequeueReusableAnnotationView(withIdentifier: identifier)
        
        if annotationView == nil {
            annotationView = MKPinAnnotationView(annotation: annotation, reuseIdentifier: identifier)
            annotationView?.canShowCallout = true
        } else {
            annotationView?.annotation = annotation
        }
        
        return annotationView
    }
    
    // MKMapViewDelegate代理方法，用于配置MKAnnotationView的弹出视图
    func mapView(_ mapView: MKMapView, didSelect view: MKAnnotationView) {
        guard let annotation = view.annotation as? CustomAnnotation else {
            return
        }
        
        // 创建自定义的弹出视图
        let popupView = UIView(frame: CGRect(x: 0, y: 0, width: 200, height: 100))
        popupView.backgroundColor = UIColor.white
        
        // 在弹出视图中显示项目的核心数据
        for project in annotation.projects {
            let nameLabel = UILabel(frame: CGRect(x: 10, y: 10, width: 180, height: 20))
            nameLabel.text = project.name
            popupView.addSubview(nameLabel)
            
            let descriptionLabel = UILabel(frame: CGRect(x: 10, y: 40, width: 180, height: 40))
            descriptionLabel.text = project.description
            descriptionLabel.numberOfLines = 2
            popupView.addSubview(descriptionLabel)
            
            // 添加其他需要显示的属性
        }
        
        view.detailCalloutAccessoryView = popupView
    }
}