How add polyline in mapView

Question

I would insert in my mapview an polyline! I made it in this way

 CLLocationCoordinate2D coord[2];
coord[1].latitude = 45.42207;
coord[1].longitude = 9.123888;
coord[2].latitude = 45.422785;
coord[2].longitude = 9.12377;

MKPolyline *polyline = [[MKPolyline alloc] init];
polyline = [MKPolyline polylineWithCoordinates:coord count:2];

[self.mapView addAnnotation:polyline];

But don't work and there's this error: EXC_BAD_ACCESS. What's it wrong?

Answer 1

try this

CLLocationCoordinate2D coord[2];
coord[0].latitude = 45.42207;
coord[0].longitude = 9.123888;
coord[1].latitude = 45.422785;
coord[1].longitude = 9.12377;

MKPolyline *polyline = [[MKPolyline alloc] init];
polyline = [MKPolyline polylineWithCoordinates:coord count:2];


- (MKOverlayView *)mapView:(MKMapView *)mapView viewForOverlay:(id <MKOverlay>)overlay {

    MKPolylineView *polyLineView = [[MKPolylineView alloc] initWithPolyline:polyline];
    polyLineView.fillColor = [UIColor blueColor];
    polyLineView.strokeColor = [UIColor greenColor];
    polyLineView.lineWidth = 7;
    return polyLineView;
}

Answer 2

Array indices in C start with index 0, not 1:

CLLocationCoordinate2D coord[2];
coord[0].latitude = 45.42207;
coord[0].longitude = 9.123888;
coord[1].latitude = 45.422785;
coord[1].longitude = 9.12377;