通过使用 MapKit 可以将地图嵌入到视图中，MapKit 框架除了可以显示地图，还支持在地图上做标记。

import UIKit
import MapKit
import CoreLocation

class ViewController: UIViewController {
    
    var mainMapView: MKMapView!
    
    //定位管理器
    let locationManager:CLLocationManager = CLLocationManager()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        //使用代码创建
        self.mainMapView = MKMapView(frame:self.view.frame)
        self.view.addSubview(self.mainMapView)
        
        //地图类型设置 - 标准地图
        self.mainMapView.mapType = MKMapType.standard
        
        //创建一个MKCoordinateSpan对象，设置地图的范围（越小越精确）
        let latDelta = 0.05
        let longDelta = 0.05
        let currentLocationSpan:MKCoordinateSpan = MKCoordinateSpanMake(latDelta, longDelta)
        
        //定义地图区域和中心坐标（
        //使用当前位置
        //var center:CLLocation = locationManager.location.coordinate
        //使用自定义位置
        let center:CLLocation = CLLocation(latitude: 32.029171, longitude: 118.788231)
        let currentRegion:MKCoordinateRegion = MKCoordinateRegion(center: center.coordinate,
            span: currentLocationSpan)
        
        //设置显示区域
        self.mainMapView.setRegion(currentRegion, animated: true)
        
        //创建一个大头针对象
        let objectAnnotation = MKPointAnnotation()
        //设置大头针的显示位置
        objectAnnotation.coordinate = CLLocation(latitude: 32.029171,
            longitude: 118.788231).coordinate
        //设置点击大头针之后显示的标题
        objectAnnotation.title = "南京夫子庙"
        //设置点击大头针之后显示的描述
        objectAnnotation.subtitle = "南京市秦淮区秦淮河北岸中华路"
        //添加大头针
        self.mainMapView.addAnnotation(objectAnnotation)
    }
}

5，标记样式的修改
默认标记是一个红色的大头针。通过MKMapViewDelegate代理，我们可以自定义大头针的样式，以及点击注释视图右侧按钮样式等。

import UIKit
import MapKit
import CoreLocation

class ViewController: UIViewController, MKMapViewDelegate {
    
    var mainMapView: MKMapView!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        //使用代码创建
        self.mainMapView = MKMapView(frame:self.view.frame)
        self.view.addSubview(self.mainMapView)
        
        self.mainMapView.delegate = self
        
        //添加大头针等相关代码（这个同前面一样，就不再写了）
        //.......
    }
    
    //自定义大头针样式
    func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation)
        -> MKAnnotationView? {
        if annotation is MKUserLocation {
            return nil
        }
        
        let reuserId = "pin"
        var pinView = mapView.dequeueReusableAnnotationView(withIdentifier: reuserId)
            as? MKPinAnnotationView
        if pinView == nil {
            //创建一个大头针视图
            pinView = MKPinAnnotationView(annotation: annotation, reuseIdentifier: reuserId)
            pinView?.canShowCallout = true
            pinView?.animatesDrop = true
            //设置大头针颜色
            pinView?.pinTintColor = UIColor.green
            //设置大头针点击注释视图的右侧按钮样式
            pinView?.rightCalloutAccessoryView = UIButton(type: .detailDisclosure)
        }else{
            pinView?.annotation = annotation
        }
        
        return pinView
    }
}

6，地图代理 - MKMapViewDelegate中所有代理方法
MKMapViewDelegate除了可以设置大头针样式，注释视图点击响应等。还可以在地图相关事件发生时（比如缩放，地图加载，位置跟踪等），触发相应的方法。

import UIKit
import MapKit
import CoreLocation

class ViewController: UIViewController, MKMapViewDelegate {
    
    var mainMapView: MKMapView!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        //使用代码创建
        self.mainMapView = MKMapView(frame:self.view.frame)
        self.view.addSubview(self.mainMapView)
        
        self.mainMapView.delegate = self
    }
    
    func mapView(_ mapView: MKMapView, regionWillChangeAnimated animated: Bool) {
        print("地图缩放级别发送改变时")
    }
    
    func mapView(_ mapView: MKMapView, regionDidChangeAnimated animated: Bool) {
        print("地图缩放完毕触法")
    }
    
    func mapViewWillStartLoadingMap(_ mapView: MKMapView) {
        print("开始加载地图")
    }
    
    func mapViewDidFinishLoadingMap(_ mapView: MKMapView) {
        print("地图加载结束")
    }
    
    func mapViewDidFailLoadingMap(_ mapView: MKMapView, withError error: Error) {
        print("地图加载失败")
    }
    
    func mapViewWillStartRenderingMap(_ mapView: MKMapView) {
        print("开始渲染下载的地图块")
    }
    
    func mapViewDidFinishRenderingMap(_ mapView: MKMapView, fullyRendered: Bool) {
        print("渲染下载的地图结束时调用")
    }
    
    func mapViewWillStartLocatingUser(_ mapView: MKMapView) {
        print("正在跟踪用户的位置")
    }
    
    func mapViewDidStopLocatingUser(_ mapView: MKMapView) {
        print("停止跟踪用户的位置")
    }
    
    func mapView(_ mapView: MKMapView, didUpdate userLocation: MKUserLocation) {
        print("更新用户的位置")
    }
    
    func mapView(_ mapView: MKMapView, didFailToLocateUserWithError error: Error) {
        print("跟踪用户的位置失败")
    }
    
    func mapView(_ mapView: MKMapView, didChange mode: MKUserTrackingMode,
                 animated: Bool) {
        print("改变UserTrackingMode")
    }
    
    func mapView(_ mapView: MKMapView, rendererFor overlay: MKOverlay)
        -> MKOverlayRenderer {
        print("设置overlay的渲染")
        return MKPolylineRenderer()
    }
    
    private func mapView(mapView: MKMapView,
                         didAddOverlayRenderers renderers: [MKOverlayRenderer]) {
        print("地图上加了overlayRenderers后调用")
    }
    
    /*** 下面是大头针标注相关 *****/
    func mapView(_ mapView: MKMapView, didAdd views: [MKAnnotationView]) {
        print("添加注释视图")
    }
    
    func mapView(_ mapView: MKMapView, annotationView view: MKAnnotationView,
                 calloutAccessoryControlTapped control: UIControl) {
        print("点击注释视图按钮")
    }
    
    func mapView(_ mapView: MKMapView, didSelect view: MKAnnotationView) {
        print("点击大头针注释视图")
    }
    
    func mapView(_ mapView: MKMapView, didDeselect view: MKAnnotationView) {
        print("取消点击大头针注释视图")
    }
    
    func mapView(_ mapView: MKMapView, annotationView view: MKAnnotationView,
                 didChange newState: MKAnnotationViewDragState,
                 fromOldState oldState: MKAnnotationViewDragState) {
        print("移动annotation位置时调用")
    }
}