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POAdding multiple overlays to MKMapView
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copied!<p>I am having some trouble understanding how to add multiple overlays to MKMapView. </p> <p>I have an array routes tracked. The routes tracked are arrays of CLLocations. So I have an array of arrays. </p> <p>I am able to take one route and draw it on the map view. However, I need to draw ALL the routes onto the map view. </p> <p>So here is how I go about creating the MKPolyline for 1 route: </p> <pre><code>-(void) loadRoute { //So we grab an array that holds all the locations of one route. NSArray *locations = [[NSArray alloc] initWithArray:[routesArray objectAtIndex:0]]; // while we create the route points, we will also be calculating the bounding box of our route // so we can easily zoom in on it. MKMapPoint northEastPoint; MKMapPoint southWestPoint; // create a c array of points. MKMapPoint* pointArr = malloc(sizeof(CLLocationCoordinate2D) *[locations count]); for(int idx = 0; idx < [locations count]; idx++) { CLLocation *tempLoc = (CLLocation*)[locations objectAtIndex:idx]; CLLocationDegrees latitude = tempLoc.coordinate.latitude; CLLocationDegrees longitude = tempLoc.coordinate.longitude; // create our coordinate and add it to the correct spot in the array CLLocationCoordinate2D coordinate = CLLocationCoordinate2DMake(latitude, longitude); MKMapPoint point = MKMapPointForCoordinate(coordinate); // if it is the first point, just use them, since we have nothing to compare to yet. if (idx == 0) { northEastPoint = point; southWestPoint = point; } else { if (point.x > northEastPoint.x) northEastPoint.x = point.x; if(point.y > northEastPoint.y) northEastPoint.y = point.y; if (point.x < southWestPoint.x) southWestPoint.x = point.x; if (point.y < southWestPoint.y) southWestPoint.y = point.y; } pointArr[idx] = point; } self.routeLine = [MKPolyline polylineWithPoints:pointArr count:[locations count]]; //Zoom in to fit route on screen _routeRect = MKMapRectMake(southWestPoint.x, southWestPoint.y, northEastPoint.x - southWestPoint.x, northEastPoint.y - southWestPoint.y); // clear the memory allocated earlier for the points free(pointArr); } </code></pre> <p>Here is the MapKit delegate call that returns the overlay: </p> <pre><code>#pragma mark MKMapViewDelegate - (MKOverlayView *)mapView:(MKMapView *)mapView viewForOverlay:(id <MKOverlay>)overlay { MKOverlayView* overlayView = nil; if(overlay == self.routeLine) { //if we have not yet created an overlay view for this overlay, create it now. if(nil == self.routeLineView) { self.routeLineView = [[MKPolylineView alloc] initWithPolyline:self.routeLine]; self.routeLineView.fillColor = [UIColor redColor]; self.routeLineView.strokeColor = [UIColor redColor]; self.routeLineView.lineWidth = 3; } overlayView = self.routeLineView; } return overlayView; } </code></pre> <p>So all the code given above works fine. I can't figure out how to load more overlays to show the other routes. </p> <p>I thought that maybe in loadRoute method, running through all the routes and creating a MKOverlayView for each one. Storing all those MKOverlayView in an array then doing: [self.mapView addOverlays:array];</p> <p>But it doesn't work. The problem is that in the delegate method I somehow need to know which overlay to return. </p> <p>So if I could do something along the lines of: </p> <pre><code>- (MKOverlayView *)mapView:(MKMapView *)mapView viewForOverlay:(id <MKOverlay>)overlay { int tag = overlay.tag; return (MKOverlayView*)[arrayOfViews objectAtIndex:tag]; } </code></pre> <p>it would work fine. But unfortunately it doesn't work like that :(</p> <p>Any help would be very much appreciated! </p> <p>EDIT:</p> <p>I use this in ViewDidLoad to add the overlay:</p> <pre><code>[self loadRoute]; // add the overlay to the map if (nil != self.routeLine) { [self.mapView addOverlay:self.routeLine]; } // zoom in on the route. [self zoomInOnRoute]; </code></pre> <p>This is in the header:</p> <pre><code>// the data representing the route points. MKPolyline* _routeLine; // the view we create for the line on the map MKPolylineView* _routeLineView; // the rect that bounds the loaded points MKMapRect _routeRect; </code></pre>

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