如何在地图上添加两个不同的引脚？- Swift

import UIKit
import MapKit

class ViewController: UIViewController, MKMapViewDelegate {
    
    @IBOutlet weak var mapView: MKMapView!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        mapView.delegate = self
        
        // 创建两个不同的位置坐标
        let location1 = CLLocationCoordinate2D(latitude: 37.331686, longitude: -122.030656)
        let location2 = CLLocationCoordinate2D(latitude: 37.332693, longitude: -122.030656)
        
        // 创建两个不同的标注对象
        let annotation1 = MKPointAnnotation()
        annotation1.coordinate = location1
        annotation1.title = "位置1"
        
        let annotation2 = MKPointAnnotation()
        annotation2.coordinate = location2
        annotation2.title = "位置2"
        
        // 将标注对象添加到地图上
        mapView.addAnnotation(annotation1)
        mapView.addAnnotation(annotation2)
        
        // 设置地图的显示区域
        let region = MKCoordinateRegion(center: location1, latitudinalMeters: 500, longitudinalMeters: 500)
        mapView.setRegion(region, animated: true)
    }
    
    // 自定义标注视图
    func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView? {
        if annotation is MKUserLocation {
            return nil
        }
        
        let pinIdentifier = "PinAnnotationIdentifier"
        var pinView = mapView.dequeueReusableAnnotationView(withIdentifier: pinIdentifier) as? MKPinAnnotationView
        
        if pinView == nil {
            pinView = MKPinAnnotationView(annotation: annotation, reuseIdentifier: pinIdentifier)
            pinView?.canShowCallout = true
            pinView?.pinTintColor = .red
        } else {
            pinView?.annotation = annotation
        }
        
        return pinView
    }
}