Cannot see MKPolyline

Question

I'm trying to add a simple MKPolyline connecting two MKPinAnnotationViews. I read this tutorial and watched apple's WWDC 2010 video on it. (http://spitzkoff.com/craig/?p=136). I am just trying to draw something simple, so in viewDidLoad, I do this:

MKMapPoint *pointArray = malloc(sizeof(CLLocationCoordinate2D) * 2);
pointArray[0] = MKMapPointForCoordinate(CLLocationCoordinate2DMake(32, -115));
pointArray[1] = MKMapPointForCoordinate(CLLocationCoordinate2DMake(32, -130));

MKPolyline *line = [MKPolyline polylineWithPoints:pointArray count:2];
[self.mapView addOverlay:line];
    free(pointArray);

Then my delegate callback is:

- (MKOverlayView *)mapView:(MKMapView *)mapView viewForOverlay:(id <MKOverlay>)overlay {
    if ([overlay isKindOfClass:[MKCircle class]]) {
        MKCircleView *view = [[MKCircleView alloc] initWithOverlay:overlay];
        view.fillColor = [UIColor redColor];
        view.strokeColor = [[UIColor redColor] colorWithAlphaComponent:0.5];
        return view;
    }
    else {
        MKPolylineView *view = [[MKPolylineView alloc] initWithOverlay:overlay];
        view.fillColor = [UIColor redColor];
        view.lineWidth = 20;

    return view;
    }
}

If I do a simple example with a MKCircle, I do see the circle. With this MKPolyline that I add in viewDidLoad, I do get the mapView:viewForOverlay: callback, but nothing gets drawn on the screen. Am I missing something? Thanks.

Answer 1

An MKPolylineView uses the strokeColor to draw, not the fillColor so change:

MKPolylineView *view = [[MKPolylineView alloc] initWithOverlay:overlay];
view.fillColor = [UIColor redColor];
view.lineWidth = 20;

to:

MKPolylineView *view = [[MKPolylineView alloc] initWithOverlay:overlay];
view.strokeColor = [UIColor redColor];  // <-- stroke instead of fill
view.lineWidth = 20;