Swift - 带有图像的自定义 MKPointAnnotation [英] Swift - Custom MKPointAnnotation with Image
问题描述
我正在尝试创建一个自定义 MKPointAnnotation 以在地图视图上使用.它看起来非常像 Apple 照片中使用的那个:
I am trying to create a custom MKPointAnnotation to use on a map view. It looks very much like the one used in Apple's Photos:
我将从服务器检索一些照片及其位置.然后我想显示一个像上面那样的注释，注释里面有图像.
I will be retrieving a number of photos from a server, along with their location. I then want to display an annotation like the one above, with the image inside the annotation.
我目前有一个程序，可以在正确的坐标处添加一个普通的MKPointAnnotation，也可以从服务器检索相关照片.
I currently have a program that can add a normal MKPointAnnotation at the right coordinate, and can also retrieve the relevant photo from the server.
我想要的只是让我的 MKPointAnnotation 看起来像那样.
All I want is to style my MKPointAnnotation to look just like that.
我曾尝试遵循其他答案，但我认为这略有不同，因为我想每次都在模板上显示图像.
I have tried following other answers but I think this is slightly different because I want to show an image on a template every time.
推荐答案
func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) ->MKAnnotationView? 来自 MKMapViewDelegate 是您需要覆盖的函数.
func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView? from MKMapViewDelegate is the function you need to override.
它允许您为每个注释提供自定义"视图.在此函数中，您可以将自定义视图(MKAnnotationView 的子类)出列并设置自定义属性，或者您可以将具有属性 image<的常规 MKAnnotationView 出列/代码>.
It allows you to provide "custom" views for the each annotation. Within this function, you can either dequeue a custom view (subclass of MKAnnotationView) and set custom properties OR you can dequeue a regular MKAnnotationView which has a property image.
您可以设置该属性以显示自定义图像.无论如何，我宁愿使用我自己的 annotationView，因为您可以添加自定义布局(标签、imageViews 等)和主题(颜色、图层等).
You can set that property to display custom images. I'd rather use my own annotationView anyway as you can add custom layouts (labels, imageViews, etc..) and themes (colours, layers, etc..).
示例:
//
// ViewController.swift
// Maps
//
// Created by Brandon T on 2017-02-20.
// Copyright © 2017 XIO. All rights reserved.
//
import UIKit
import MapKit
class ImageAnnotation : NSObject, MKAnnotation {
var coordinate: CLLocationCoordinate2D
var title: String?
var subtitle: String?
var image: UIImage?
var colour: UIColor?
override init() {
self.coordinate = CLLocationCoordinate2D()
self.title = nil
self.subtitle = nil
self.image = nil
self.colour = UIColor.white
}
}
class ImageAnnotationView: MKAnnotationView {
private var imageView: UIImageView!
override init(annotation: MKAnnotation?, reuseIdentifier: String?) {
super.init(annotation: annotation, reuseIdentifier: reuseIdentifier)
self.frame = CGRect(x: 0, y: 0, width: 50, height: 50)
self.imageView = UIImageView(frame: CGRect(x: 0, y: 0, width: 50, height: 50))
self.addSubview(self.imageView)
self.imageView.layer.cornerRadius = 5.0
self.imageView.layer.masksToBounds = true
}
override var image: UIImage? {
get {
return self.imageView.image
}
set {
self.imageView.image = newValue
}
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
class ViewController: UIViewController, MKMapViewDelegate {
var mapView: MKMapView!
var locationManager: CLLocationManager!
override func viewDidLoad() {
super.viewDidLoad()
self.initControls()
self.doLayout()
self.loadAnnotations()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
func initControls() {
self.mapView = MKMapView()
self.mapView.isRotateEnabled = true
self.mapView.showsUserLocation = true
self.mapView.delegate = self
let center = CLLocationCoordinate2DMake(43.761539, -79.411079)
let region = MKCoordinateRegionMake(center, MKCoordinateSpanMake(0.005, 0.005))
self.mapView.setRegion(region, animated: true)
}
func doLayout() {
self.view.addSubview(self.mapView)
self.mapView.leftAnchor.constraint(equalTo: self.view.leftAnchor).isActive = true
self.mapView.rightAnchor.constraint(equalTo: self.view.rightAnchor).isActive = true
self.mapView.topAnchor.constraint(equalTo: self.view.topAnchor).isActive = true
self.mapView.bottomAnchor.constraint(equalTo: self.view.bottomAnchor).isActive = true
self.mapView.translatesAutoresizingMaskIntoConstraints = false
}
func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView? {
if annotation.isKind(of: MKUserLocation.self) { //Handle user location annotation..
return nil //Default is to let the system handle it.
}
if !annotation.isKind(of: ImageAnnotation.self) { //Handle non-ImageAnnotations..
var pinAnnotationView = mapView.dequeueReusableAnnotationView(withIdentifier: "DefaultPinView")
if pinAnnotationView == nil {
pinAnnotationView = MKPinAnnotationView(annotation: annotation, reuseIdentifier: "DefaultPinView")
}
return pinAnnotationView
}
//Handle ImageAnnotations..
var view: ImageAnnotationView? = mapView.dequeueReusableAnnotationView(withIdentifier: "imageAnnotation") as? ImageAnnotationView
if view == nil {
view = ImageAnnotationView(annotation: annotation, reuseIdentifier: "imageAnnotation")
}
let annotation = annotation as! ImageAnnotation
view?.image = annotation.image
view?.annotation = annotation
return view
}
func loadAnnotations() {
let request = NSMutableURLRequest(url: URL(string: "https://i.imgur.com/zIoAyCx.png")!)
request.httpMethod = "GET"
let session = URLSession(configuration: URLSessionConfiguration.default)
let dataTask = session.dataTask(with: request as URLRequest) { (data, response, error) in
if error == nil {
let annotation = ImageAnnotation()
annotation.coordinate = CLLocationCoordinate2DMake(43.761539, -79.411079)
annotation.image = UIImage(data: data!, scale: UIScreen.main.scale)
annotation.title = "Toronto"
annotation.subtitle = "Yonge & Bloor"
DispatchQueue.main.async {
self.mapView.addAnnotation(annotation)
}
}
}
dataTask.resume()
}
}
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