iOS：加载 MKMapView 并添加注释叠加时的通知

使用MKMapView加载地图并添加注释/叠加时，可以使用以下通知来获取相关的信息和状态变化：

swift
import MapKit
class MapViewController: UIViewController, MKMapViewDelegate {
    
    @IBOutlet weak var mapView: MKMapView!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        mapView.delegate = self
        
        // 设置地图的显示区域和缩放级别
        let initialLocation = CLLocation(latitude: 37.7749, longitude: -122.4194)
        let regionRadius: CLLocationDistance = 1000
        let coordinateRegion = MKCoordinateRegion(center: initialLocation.coordinate, latitudinalMeters: regionRadius, longitudinalMeters: regionRadius)
        mapView.setRegion(coordinateRegion, animated: true)
        
        // 添加注释
        let annotation = MKPointAnnotation()
        annotation.coordinate = initialLocation.coordinate
        annotation.title = "San Francisco"
        annotation.subtitle = "California"
        mapView.addAnnotation(annotation)
    }
    
    // MKMapViewDelegate方法
    func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView? {
        if annotation is MKUserLocation {
            return nil
        }
        
        let identifier = "AnnotationIdentifier"
        var annotationView = mapView.dequeueReusableAnnotationView(withIdentifier: identifier) as? MKPinAnnotationView
        
        if annotationView == nil {
            annotationView = MKPinAnnotationView(annotation: annotation, reuseIdentifier: identifier)
            annotationView?.canShowCallout = true
        } else {
            annotationView?.annotation = annotation
        }
        
        return annotationView
    }
}

swift
import UIKit
import MapKit
class MapViewController: UIViewController, MKMapViewDelegate {
    
    @IBOutlet weak var mapView: MKMapView!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        mapView.delegate = self
        
        NotificationCenter.default.addObserver(self, selector: #selector(mapViewWillStartLoadingMap), name: .MKMapViewWillStartLoadingMap, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(mapViewDidFinishLoadingMap), name: .MKMapViewDidFinishLoadingMap, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(mapViewDidFailLoadingMap), name: .MKMapViewDidFailLoadingMap, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(mapViewWillStartRenderingMap), name: .MKMapViewWillStartRenderingMap, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(mapViewDidFinishRenderingMap), name: .MKMapViewDidFinishRenderingMap, object: nil)
    }
    
    deinit {
        NotificationCenter.default.removeObserver(self)
    }
    
    @objc func mapViewWillStartLoadingMap() {
        print("地图开始加载")
    }
    
    @objc func mapViewDidFinishLoadingMap() {
        print("地图加载完成")
    }
    
    @objc func mapViewDidFailLoadingMap() {
        print("地图加载失败")
    }
    
    @objc func mapViewWillStartRenderingMap() {
        print("地图开始渲染")
    }
    
    @objc func mapViewDidFinishRenderingMap() {
        print("地图渲染完成")
    }
    
    // 其他代码...
}