Что вам, вероятно, нужно будет сделать, это сохранить MKPointAnnotation s как Data в UserDefaults.Для этого вы создадите массив словарей из всех аннотаций mapView:
func addPin(_ sender: UILongPressGestureRecognizer) {
let location = sender.location(in: self.mapView)
let locCoord = self.mapView.convert(location, toCoordinateFrom: self.mapView)
let annotation = MKPointAnnotation()
annotation.coordinate = locCoord
annotation.title = titleTextField.text
self.mapView.addAnnotation(annotation)
//Create a dictionary from the annotation
let newAnnotationDict = [
"lat": locCoord.latitude
"lng": locCoord.longitude
"title": annotation.title
]
//Pull the stored annotations data
var annotationsArray: [[String:Any]]!
var annotationsData = UserDefaults.standard.data(forKey: "StoredAnnotations")
//If the data is nil, then set the new annotation as the only element in the array
if annotationsData == nil {
annotationsArray = [newAnnotationDict]
} else {
//If it isn't nil, then convert the data into an array of dicts
do {
//Convert this data into an array of dicts
annotationsArray = try JSONSerialization.jsonObject(with: annotationsData, options: []) as! [[String:Any]]
annotationsArray.append(newAnnotationDict)
} catch {
print(error.localizedDescription)
}
}
do {
//Use JSONSerialization to convert the annotationsArray into Data
let jsonData = try JSONSerialization.data(withJSONObject: annotationsArray, options: .prettyPrinted)
//Store this data in UserDefaults
UserDefaults.standard.set(jsonData, forKey: "StoredAnnotations")
} catch {
print(error.localizedDescription)
}
print("This will become the annotation title: \(titleTextField.text).")
print(annotation.coordinate.latitude, annotation.coordinate.longitude)
}
И затем, когда контроллер представления снова откроется, вы захотите извлечь это Data изUserDefaults и разберите его на массив MKPointAnnotation объектов.
class MapViewController: UIViewController {
//Whenever the view loads, check if there were any annotations stored last time
override func viewDidLoad() {
super.viewDidLoad()
//Check if the data for "StoredAnnotations" exists
if UserDefaults.standard.data(forKey: "StoredAnnotations") != nil {
var storedAnnotationObjects = [MKPointAnnotation]()
do {
//Get the data from UserDefaults
let storedAnnotationsData = UserDefaults.standard.data(forKey: "StoredAnnotations")!
//Convert this data into an array of dictionaries
let storedAnnotationsArray = try JSONSerialization.jsonObject(with: storedAnnotationsData, options: []) as! [[String:Any]]
for dict in storedAnnotationsArray {
//Initialize a new annotation and set the annotation's properties
let newAnnotation = MKPointAnnotation()
newAnnotation.coordinate = CLLocationCoordinate2D(latitude: dict["lat"] as! CGFloat, longitude: dict["lng"] as! CGFloat)
newAnnotation.title = dict["title"] as! String
newAnnotationObjects.append(newAnnotation)
}
//Add the annotation to the mapView
self.mapView.annotations = storedAnnotationObjects
} catch {
print(error.localizedDescription)
}
}
}
...
}
Если аннотации удаляются, вам необходимо аналогичным образом преобразовать сохраненные данные в массив dicts и удалить соответствующий объект.и обновите данные.