How to use Custom MKAnnotationView in viewcontroller - ios

Question

Swift - Custom MKAnnotationView, set label title
This link tells me how to create the custom annotation. I am new to IoS app. Trying to understand how to use this in the code.
I want to change the font in the call and have 2 lines instead of one. It appears this class can do all that, but I do not know how to use this in the view controller to change the font. Currently, this is what I have and have created the class as suggested in the link:
let annotation = MKPointAnnotation()
annotation.coordinate = coordinate
annotation.title=title
self.map.addAnnotation(annotation)
How do I change this to use the custom class?
THanks
Ram

Answer 1

How do I change this to use the custom class?
You have to understand that there's a difference between an annotation and an annotation view. The former is an object that's associated with some point or region of a map. You add annotations to a map view, and then the map view takes care of figuring out when a particular annotation needs to be displayed so that you don't have to worry about what part of the map is visible, what the zoom level is, etc. You can create subclasses of MKAnnotation if you want to store some kind of custom data in the annotation itself. For example, there's a MKUserAnnotation subclass that adds a heading property; you can do the same kind of thing in your own annotation subclass.
An annotation view provides the visual representation of an annotation. A map view can have hundreds or thousands of annotations, but usually only a handful of those will need to be displayed at any moment. When a map view wants to display an annotation, it calls it's delegate's mapView(_:viewFor:) method, and the delegate returns an appropriate annotation view configured for the annotation in question. If you want to use your own MKAnnotationView subclass, as your question title indicates, then you should implement mapView(_:viewFor:) in your map view delegate such that it instantiates* an instance of your custom MKAnnotationView subclass, configures it, and returns it.
*Before your map view delegate actually creates a new annotation view, you should call the map view's dequeueReusableAnnotationView(withIdentifier:) method, which may return a view that you can use instead of creating a new one. Reusing annotation views is a lot like the way UITableView reuses table cells; in both cases the idea is to avoid constantly creating and destroying short-lived views. This is all explained in the docs, so look there for a complete explanation.

Answer 2

You need to implement the delegate methods for the MKMapView:
import UIKit
import MapKit
extension MapVC: MKMapViewDelegate, CLLocationManagerDelegate
{
func mapView(mapView: MKMapView, annotationView view: MKAnnotationView, calloutAccessoryControlTapped control: UIControl)
{
...
}
func mapView(mapView: MKMapView!, viewForAnnotation annotation: MKAnnotation!) -> MKAnnotationView! {
if annotation is MKUserLocation {
//return nil so map view draws "blue dot" for standard user location
return nil
}
let reuseId = "pin"
var pinView = mapView.dequeueReusableAnnotationViewWithIdentifier(reuseId) as? MKPinAnnotationView
if pinView == nil {
pinView = MKPinAnnotationView(annotation: annotation, reuseIdentifier: reuseId)
pinView.canShowCallout = true
pinView.animatesDrop = true
pinView.pinColor = .Purple
}
else {
pinView!.annotation = annotation
}
return pinView
}
}
Instead of creating custom annotation view you can use the MKPointAnnotation as you started with your code just set :
annotation.canShowCallout = true