Multiple Locations in apple watch - ios

Question

I had to show locations around the user location. The locations info will arrive from the server. I am using 'for' loop to parse the location and add to map with annotation pin. As of now, it shows only the last arrived location. But the requirement is such that multiple locations should be shown with user location as Center point. As of now I am able to show only one pin. Please help how to achieve this?
for (NSDictionary* dictionary in responseDict)
{
NSString *latitudeString=[NSString stringWithFormat:#"%#",[dictionary valueForKey:#"LATITUDE"]];
double latitude=[latitudeString doubleValue];
NSString *longitudeString=[NSString stringWithFormat:#"%#",[dictionary valueForKey:#"LONGITUDE"]];
double longitude=[longitudeString doubleValue];
NSLog(#"the LATITUDE AND LONGITUDE is %f, %f",latitude,longitude);
CLLocationCoordinate2D locationCoordinate;
locationCoordinate.latitude=latitude;
locationCoordinate.longitude=longitude;
[self.mapView addAnnotation:locationCoordinate withPinColor:WKInterfaceMapPinColorPurple];
MKCoordinateSpan coordinateSpan = MKCoordinateSpanMake(0.05, 0.05);
[self.mapView setRegion:(MKCoordinateRegionMake(locationCoordinate, coordinateSpan))];
}
`

Answer 1

You zoom on a single location in each iteration of the loop, so eventually you end up zoomed on the last location. Sadly WKInterfaceMap doesn't have a showAnnotations method as MKMapView does, so you need to write a function yourself to achieve showing an MKCoordinateRegion including several annotations.
I haven't written any Obj-C for a while, but here's the function in Swift that shows two annotations on a Map and works on watchOS:
func showTwoMapCoordinates(first: CLLocationCoordinate2D, second: CLLocationCoordinate2D)->MKCoordinateRegion{
let center = CLLocationCoordinate2D(latitude: (first.latitude+second.latitude)/2, longitude: (first.longitude+second.longitude)/2)
var latDelta:CLLocationDegrees {
let delta = abs((first.latitude-second.latitude)*1.4)
if delta > 0 {
return delta
} else {
return 0.1
}
}
var lonDelta:CLLocationDegrees {
let delta = abs((first.longitude-second.longitude)*1.4)
if delta > 0 {
return delta
} else {
return 0.1
}
}
let span = MKCoordinateSpan(latitudeDelta: latDelta, longitudeDelta: lonDelta)
return MKCoordinateRegion(center: center, span: span)
}
To extend this to n points, where n>2, all you need to do is iterate through each pair of points you want to display, find the maximum deltas the same way as in the function above and set the center and span using the function above called on the two points that yielded the max deltas.