Draw GeoJson on Apple Maps as an overlay

Question

Can someone tell me how I can draw a GeoJson file as an overlay on Apple maps? I want a complete example, do I have shapes like Polygons or Polygons?

This GeoJSON Country file is enough for me if you provided me with a code or library to render it using MKMapView

Answer 1

I found a solution if someone wants to help too.

 @interface HHLViewController + (NSArray *)countriesOverlays; @end @implementation HHLViewController - (void)viewDidLoad { [super viewDidLoad]; NSArray *overlays = [HHLViewController countriesOverlays]; [self.stateMapView addOverlays:overlays]; } + (NSArray *)countriesOverlays { NSString *fileName = [[NSBundle mainBundle] pathForResource:@"countries" ofType:@"json"]; NSData *overlayData = [NSData dataWithContentsOfFile:fileName]; NSArray *countries = [[NSJSONSerialization JSONObjectWithData:overlayData options:NSJSONReadingAllowFragments error:nil] objectForKey:@"features"]; NSMutableArray *overlays = [NSMutableArray array]; for (NSDictionary *country in countries) { NSDictionary *geometry = country[@"geometry"]; if ([geometry[@"type"] isEqualToString:@"Polygon"]) { MKPolygon *polygon = [HHLViewController overlaysFromPolygons:geometry[@"coordinates"] id:country[@"properties"][@"name"]]; if (polygon) { [overlays addObject:polygon]; } } else if ([geometry[@"type"] isEqualToString:@"MultiPolygon"]){ for (NSArray *polygonData in geometry[@"coordinates"]) { MKPolygon *polygon = [HHLViewController overlaysFromPolygons:polygonData id:country[@"properties"][@"name"]]; if (polygon) { [overlays addObject:polygon]; } } } else { NSLog(@"Unsupported type: %@", geometry[@"type"]); } } return overlays; } + (MKPolygon *)overlaysFromPolygons:(NSArray *)polygons id:(NSString *)title { NSMutableArray *interiorPolygons = [NSMutableArray arrayWithCapacity:[polygons count] - 1]; for (int i = 1; i < [polygons count]; i++) { [interiorPolygons addObject:[HHLViewController polygonFromPoints:polygons[i] interiorPolygons:nil]]; } MKPolygon *overlayPolygon = [HHLViewController polygonFromPoints:polygons[0] interiorPolygons:interiorPolygons]; overlayPolygon.title = title; return overlayPolygon; } + (MKPolygon *)polygonFromPoints:(NSArray *)points interiorPolygons:(NSArray *)polygons { NSInteger numberOfCoordinates = [points count]; CLLocationCoordinate2D *polygonPoints = malloc(numberOfCoordinates * sizeof(CLLocationCoordinate2D)); NSInteger index = 0; for (NSArray *pointArray in points) { polygonPoints[index] = CLLocationCoordinate2DMake([pointArray[1] floatValue], [pointArray[0] floatValue]); index++; } MKPolygon *polygon; if (polygons) { polygon = [MKPolygon polygonWithCoordinates:polygonPoints count:numberOfCoordinates interiorPolygons:polygons]; } else { polygon = [MKPolygon polygonWithCoordinates:polygonPoints count:numberOfCoordinates]; } free(polygonPoints); return polygon; } @end 

Answer 2

I made several versions of Swift for MultiPolygon

 import Foundation import MapKit struct MapGeoGeometry: Codable { let type: String let coordinates: [[[[Double]]]] } struct MapGeoFeature: Codable { let type: String let geometry: MapGeoGeometry } extension MapGeoFeature { func toPolygons() -> [MKPolygon] { return geometry.coordinates .map { data in return data.map { MapGeoFeature.polygon(from: $0) } } .reduce([], +) } static func polygon(from points: [[Double]]) -> MKPolygon { let coords = points.map { CLLocationCoordinate2D(latitude: $0[1], longitude: $0[0]) } return MKPolygon(coordinates: coords, count: coords.count, interiorPolygons: nil) } }