Mapkit Annotations Disappearing

MapKit Annotations Disappearing

NiltiakSivad's solution works but it reverts to the old iOS 10 look. If you want to keep the new iOS 11 balloon markers for iOS 11 and use the old pin look only for older iOS versions then you can implement the delegate method as below:

func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView? {
    let reuseIdentifier = "annotationView"
    var view = mapView.dequeueReusableAnnotationView(withIdentifier: reuseIdentifier)
    if #available(iOS 11.0, *) {
        if view == nil {
            view = MKMarkerAnnotationView(annotation: annotation, reuseIdentifier: reuseIdentifier)
        }
        view?.displayPriority = .required
    } else {
        if view == nil {
            view = MKPinAnnotationView(annotation: annotation, reuseIdentifier: reuseIdentifier)
        }
    }
    view?.annotation = annotation
    view?.canShowCallout = true
    return view
}

How to fix custom Point Annotations from disappearing from overlap?

You apparently haven’t set the delegate for your map view because those annotation views are not MKPinAnnotationView, but rather the default MKMarkerAnnotationView. If you’re going to implement MKMapViewDelegate methods, you have to set the delegate of the map view (either in IB or programmatically).

This disappearing act is because the default MKMarkerAnnotationView is configured to enable clustering but you haven’t registered a MKMapViewDefaultClusterAnnotationViewReuseIdentifier.

So, if you really want pin annotation views and you don’t want clustering, set your map view’s delegate and your method should accomplish what you want.

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I’d personally suggest you reduce view controller bloat by moving the configuration of your annotation view into a MKPinAnnotationView subclass:

class CustomAnnotationView: MKPinAnnotationView { // or use `MKMarkerAnnotationView` if you want
    override init(annotation: MKAnnotation?, reuseIdentifier: String?) {
        super.init(annotation: annotation, reuseIdentifier: reuseIdentifier)
        displayPriority = .required
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}

Then, if you’re targeting iOS 11 and later, in your viewDidLoad, you can register your class, and you don’t have to implement mapView(_:viewFor:) at all:

mapView.register(CustomAnnotationView.self, forAnnotationViewWithReuseIdentifier: MKMapViewDefaultAnnotationViewReuseIdentifier)

Or, if you want to enjoy clustering properly, you can expand your CustomAnnotationView:

class CustomAnnotationView: MKPinAnnotationView { // or use `MKMarkerAnnotationView` if you want
    static let preferredClusteringIdentifier: String? = Bundle.main.bundleIdentifier! + ".CustomAnnotationView"

    override init(annotation: MKAnnotation?, reuseIdentifier: String?) {
        super.init(annotation: annotation, reuseIdentifier: reuseIdentifier)
        clusteringIdentifier = CustomAnnotationView.preferredClusteringIdentifier
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    override var annotation: MKAnnotation? {
        didSet {
            clusteringIdentifier = CustomAnnotationView.preferredClusteringIdentifier
        }
    }
}

And then register both your annotation view and a cluster annotation view:

mapView.register(CustomAnnotationView.self, forAnnotationViewWithReuseIdentifier: MKMapViewDefaultAnnotationViewReuseIdentifier)
mapView.register(MKMarkerAnnotationView.self, forAnnotationViewWithReuseIdentifier: MKMapViewDefaultClusterAnnotationViewReuseIdentifier)

Then you enjoy clustering with minimal effort.

annotations not appearing on MapKit

A few observations:

• Regarding not seeing the blue dot, the question is whether you set showsUserLocation (either programmatically or in the NIB/storyboard).

• Regarding annotations not showing up, you need to narrow down the problem. I would temporarily remove the mapView(_:viewFor:) and see whether you see annotations at that point.

  • If they do, then the problem is either in mapView(_:viewFor:) (see below) or your custom annotation view subclass.
  • If they do not appear, then the problem is either in your logic of how/when you added annotation or in your custom annotation class.
  • With mapView(_:viewFor:) removed, you could then try adding a MKPointAnnotation, rather than your SuperMarketAnnotation. That will help you figure out whether the problem is in your annotation class or the the logic about when and where you add annotations.

• FWIW, the mapView(_:viewFor:) has a little bug (which may or may not be related). If you successfully dequeue an existing annotation view, you just return it and never update its annotation property. You must update the annotation of any dequeued annotation view or else it will point to the old annotation (and, specifically, its old coordinate).

  if let view = mapView.dequeueReusableAnnotationView(withIdentifier: SuperMarketAnnotationView.reuseID) {
      view.annotation = annotation // make sure you update the annotation for dequeued annotation view
      return view
  }
  

Annotations are hidden when zooming out

The current user's annotation doesn't have a cluster identifier. If you provide a cluster identifier for the current user's annotation, it works.

Why does a custom MKMapView annotation image disappear on touch?

Answering my own question here, just in case others have the same issue. Notice that I am using "MKPinAnnotationView" - it should be changed to "MKAnnotationView" and everything works.

Fixed code:

- (MKAnnotationView *)mapView:(MKMapView *)newMapView viewForAnnotation:(id )newAnnotation {
    MKAnnotationView *annotation = [[MKAnnotationView alloc] initWithAnnotation:newAnnotation reuseIdentifier:@"currentloc"];

    if (annotation == nil) {
        annotation = [[MKAnnotationView alloc] initWithAnnotation:newAnnotation reuseIdentifier:@"currentloc"];
    }

    annotation.image = [UIImage imageNamed:@"anno.png"];
    annotation.canShowCallout = YES;
    annotation.rightCalloutAccessoryView = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
    UIImageView *imgView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"bus_stop_30x30.png"]];
    annotation.leftCalloutAccessoryView = imgView;

    return annotation;
}

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