版本记录

前言

MapKit框架直接从您的应用界面显示地图或卫星图像，调出兴趣点，并确定地图坐标的地标信息。接下来几篇我们就一起看一下这个框架。感兴趣的看下面几篇文章。
1. MapKit框架详细解析（一） —— 基本概览（一）
2. MapKit框架详细解析（二） —— 基本使用简单示例（一）
3. MapKit框架详细解析（三） —— 基本使用简单示例（二）
4. MapKit框架详细解析（四） —— 一个叠加视图相关的简单示例（一）
5. MapKit框架详细解析（五） —— 一个叠加视图相关的简单示例（二）
6. MapKit框架详细解析（六） —— 添加自定义图块（一）
7. MapKit框架详细解析（七） —— 添加自定义图块（二）
8. MapKit框架详细解析（八） —— 添加自定义图块（三）
9. MapKit框架详细解析（九） —— 地图特定区域放大和创建自定义地图annotations（一）

源码

1. Swift

首先看下工程组织结构

下面就是源码了

1. ViewController.swift

import UIKit
import MapKit

class ViewController: UIViewController {
  @IBOutlet private var mapView: MKMapView!
  private var artworks: [Artwork] = []
  
  override func viewDidLoad() {
    super.viewDidLoad()
    // Set initial location in Honolulu
    let initialLocation = CLLocation(latitude: 21.282778, longitude: -157.829444)
    mapView.centerToLocation(initialLocation)
    
    let oahuCenter = CLLocation(latitude: 21.4765, longitude: -157.9647)
    let region = MKCoordinateRegion(
      center: oahuCenter.coordinate,
      latitudinalMeters: 50000,
      longitudinalMeters: 60000)
    mapView.setCameraBoundary(
      MKMapView.CameraBoundary(coordinateRegion: region),
      animated: true)
    
    let zoomRange = MKMapView.CameraZoomRange(maxCenterCoordinateDistance: 200000)
    mapView.setCameraZoomRange(zoomRange, animated: true)
    
    mapView.delegate = self
    
    mapView.register(
      ArtworkView.self,
      forAnnotationViewWithReuseIdentifier: MKMapViewDefaultAnnotationViewReuseIdentifier)
    
    loadInitialData()
    mapView.addAnnotations(artworks)
  }
  
  private func loadInitialData() {
    // 1
    guard
      let fileName = Bundle.main.url(forResource: "PublicArt", withExtension: "geojson"),
      let artworkData = try? Data(contentsOf: fileName)
      else {
        return
    }
    
    do {
      // 2
      let features = try MKGeoJSONDecoder()
        .decode(artworkData)
        .compactMap { $0 as? MKGeoJSONFeature }
      // 3
      let validWorks = features.compactMap(Artwork.init)
      // 4
      artworks.append(contentsOf: validWorks)
    } catch {
      // 5
      print("Unexpected error: \(error).")
    }
  }
}

private extension MKMapView {
  func centerToLocation(_ location: CLLocation, regionRadius: CLLocationDistance = 1000) {
    let coordinateRegion = MKCoordinateRegion(
      center: location.coordinate,
      latitudinalMeters: regionRadius,
      longitudinalMeters: regionRadius)
    setRegion(coordinateRegion, animated: true)
  }
}

extension ViewController: MKMapViewDelegate {
  func mapView(
    _ mapView: MKMapView,
    annotationView view: MKAnnotationView,
    calloutAccessoryControlTapped control: UIControl
  ) {
    guard let artwork = view.annotation as? Artwork else {
      return
    }
    
    let launchOptions = [MKLaunchOptionsDirectionsModeKey: MKLaunchOptionsDirectionsModeDriving]
    artwork.mapItem?.openInMaps(launchOptions: launchOptions)
  }
}

2. Artwork.swift

import Foundation
import MapKit
import Contacts

class Artwork: NSObject, MKAnnotation {
  let title: String?
  let locationName: String?
  let discipline: String?
  let coordinate: CLLocationCoordinate2D
  
  init(
    title: String?,
    locationName: String?,
    discipline: String?,
    coordinate: CLLocationCoordinate2D
  ) {
    self.title = title
    self.locationName = locationName
    self.discipline = discipline
    self.coordinate = coordinate
    
    super.init()
  }
  
  init?(feature: MKGeoJSONFeature) {
    // 1
    guard
      let point = feature.geometry.first as? MKPointAnnotation,
      // 2
      let propertiesData = feature.properties,
      let json = try? JSONSerialization.jsonObject(with: propertiesData),
      let properties = json as? [String: Any]
      else {
        return nil
    }
    
    // 3
    title = properties["title"] as? String
    locationName = properties["location"] as? String
    discipline = properties["discipline"] as? String
    coordinate = point.coordinate
    super.init()
  }
  
  var subtitle: String? {
    return locationName
  }
  
  var mapItem: MKMapItem? {
    guard let location = locationName else {
      return nil
    }
    
    let addressDict = [CNPostalAddressStreetKey: location]
    let placemark = MKPlacemark(
      coordinate: coordinate,
      addressDictionary: addressDict)
    let mapItem = MKMapItem(placemark: placemark)
    mapItem.name = title
    return mapItem
  }
  
  var markerTintColor: UIColor  {
    switch discipline {
    case "Monument":
      return .red
    case "Mural":
      return .cyan
    case "Plaque":
      return .blue
    case "Sculpture":
      return .purple
    default:
      return .green
    }
  }
  
  var image: UIImage {
    guard let name = discipline else { return #imageLiteral(resourceName: "Flag") }
    
    switch name {
    case "Monument":
      return #imageLiteral(resourceName: "Monument")
    case "Sculpture":
      return #imageLiteral(resourceName: "Sculpture")
    case "Plaque":
      return #imageLiteral(resourceName: "Plaque")
    case "Mural":
      return #imageLiteral(resourceName: "Mural")
    default:
      return #imageLiteral(resourceName: "Flag")
    }
  }
}

3. ArtworkViews.swift

import Foundation
import MapKit

class ArtworkMarkerView: MKMarkerAnnotationView {
  override var annotation: MKAnnotation? {
    willSet {
      // 1
      guard let artwork = newValue as? Artwork else {
        return
      }
      canShowCallout = true
      calloutOffset = CGPoint(x: -5, y: 5)
      rightCalloutAccessoryView = UIButton(type: .detailDisclosure)

      // 2
      markerTintColor = artwork.markerTintColor
      glyphImage = artwork.image
    }
  }
}

class ArtworkView: MKAnnotationView {
  override var annotation: MKAnnotation? {
    willSet {
      guard let artwork = newValue as? Artwork else {
        return
      }

      canShowCallout = true
      calloutOffset = CGPoint(x: -5, y: 5)
      let mapsButton = UIButton(frame: CGRect(origin: CGPoint.zero, size: CGSize(width: 48, height: 48)))
      mapsButton.setBackgroundImage(#imageLiteral(resourceName: "Map"), for: .normal)
      rightCalloutAccessoryView = mapsButton

      image = artwork.image
      
      let detailLabel = UILabel()
      detailLabel.numberOfLines = 0
      detailLabel.font = detailLabel.font.withSize(12)
      detailLabel.text = artwork.subtitle
      detailCalloutAccessoryView = detailLabel
    }
  }
}

后记

本篇主要介绍了地图特定区域放大和创建自定义地图annotations，感兴趣的给个赞或者关注~~~