display route on iOS 7 maps: addOverlay has no effect - ios

Question

i want display a point to point route inside my mapView, i use this code for create the route:
- (IBAction)backToYourCar {
MKPlacemark *sourcePlacemark = [[MKPlacemark alloc] initWithCoordinate:self.annotationForCar.coordinate addressDictionary:nil];
NSLog(#"coordiante : locationIniziale %f", sourcePlacemark.coordinate.latitude);
MKMapItem *carPosition = [[MKMapItem alloc] initWithPlacemark:sourcePlacemark];
MKMapItem *actualPosition = [MKMapItem mapItemForCurrentLocation];
NSLog(#"coordiante : source %f, ActualPosition %f", carPosition.placemark.coordinate.latitude ,actualPosition.placemark.coordinate.latitude);
MKDirectionsRequest *request = [[MKDirectionsRequest alloc] init];
request.source = actualPosition;
request.destination = carPosition;
request.requestsAlternateRoutes = YES;
MKDirections *directions = [[MKDirections alloc] initWithRequest:request];
[directions calculateDirectionsWithCompletionHandler:^(MKDirectionsResponse *response, NSError *error) {
if (error) {
NSLog(#"Error : %#", error);
}
else {
[self showDirections:response]; //response is provided by the CompletionHandler
}
}];
}
and this for show the route on the map:
- (void)showDirections:(MKDirectionsResponse *)response
{
for (MKRoute *route in response.routes) {
[self.mapView addOverlay:route.polyline level:MKOverlayLevelAboveRoads];
}
}
actually this code does nothing.
if i try to print the the distance of route i get the correct value:
route distance: 1910.000000
then the route is right, but i can't understand why it doesn't appear on the map!
Any suggestions?

Answer 1

after a day of research i have solved with this 3 steps:
Set the delegate (self.mapView.delegate = self).
import the MKMapViewDelegate
Implemente the new iOS7 MapView delegate method:
- (MKOverlayRenderer *)mapView:(MKMapView *)mapView rendererForOverlay(id<MKOverlay>)overlay:
this is my implementation:
- (MKOverlayRenderer *)mapView:(MKMapView *)mapView rendererForOverlay:(id<MKOverlay>)overlay
{
if ([overlay isKindOfClass:[MKPolyline class]]) {
MKPolyline *route = overlay;
MKPolylineRenderer *routeRenderer = [[MKPolylineRenderer alloc] initWithPolyline:route];
routeRenderer.strokeColor = [UIColor blueColor];
return routeRenderer;
}
else return nil;
}
this method is automatically called by the delegate when you add the polyline on the map.