如何在MapView中快速添加多个注释或图钉

Question

I am developing an application which locates the current user location and displays the nearest sport centers to the user's current location. At the moment I am adding the latitude and longitude manually into the viewDidLoad() .

override func viewDidLoad() {

    super.viewDidLoad()
    let pinLocation: CLLocationCoordinate2D = CLLocationCoordinate2DMake(43.0757,25.6172)
    let objectAnn = MKPointAnnotation()
    objectAnn.coordinate = pinLocation
    objectAnn.title = "Fitnes"
    objectAnn.subtitle = "Power"
    self.MapView.addAnnotation(objectAnn)

    let pinLocation2: CLLocationCoordinate2D = CLLocationCoordinate2DMake(43.0657,25.6272)
    let objectAnn2 = MKPointAnnotation()
    objectAnn2.coordinate = pinLocation2
    objectAnn2.title = "Swimming Pool"
    objectAnn2.subtitle = "Aqua"
    self.MapView.addAnnotation(objectAnn2)
}

Is it possible to save the latitude and longitude coordinates in a JSON file and when the user opens the app, they are uploaded automatically into the function?

Also is it possible out of the coordinations the application to calculate the distance, so that the user is able to set a (km) range and see only these places which are near him?

I would be glad if you provide me with an simple code.

Answer 1

You asked:

Is it possible to save the latitude and longitude coordinates in a JSON file and when the user opens the app, they are uploaded automatically into the function?

Yes, build a dictionary with the latitude and longitude values and then use NSJSONSerialization to convert back and forth between that dictionary and a NSData that can be saved to (and read from) a file. If this is just for your own purposes, you can also read and write NSDictionary values directly to a file, without needing JSON. JSON is excellent, though, if you're going to be sending and receiving this data with external resources, such as a web service.

Also is it possible out of the coordinations the application to calculate the distance, so that the user is able to set a (km) range and see only these places which are near him?

Sure, create CLLocation objects from the CLLocationCoordinate2D values. And then you can use distanceFromLocation to calculate the distance between two CLLocation objects.