Question

Im trying to show a callout when user taps on an overlay. The callout then has a title on it based on the selected overlay. I want the annotations to be shown only when users taps on an overlay. but the problem is that the overlay doesnt recognize the tap and all the annotations are visible at start. I want them hidden.

a similiar question is here. but I cant figure it out.
Show callout when tapping overlay

overlays coordinations are downloaded from the server and added like this:

 //Add a polygon
        MKPolygon *rect=[MKPolygon polygonWithCoordinates:parkingCords count:5];
        [self.mapView addOverlay:rect];
        [self.mapView addAnnotation:rect];

Each overlay has now an Annotation in its centre.

ViewForAnnotation

- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation{

...
 else if([annotation isKindOfClass:[MKPolygon class]]){
        NSLog(@"MKPOLYGON CLASS");
        static NSString *identifier3 = @"else";  
        MKPinAnnotationView *annotationView = (MKPinAnnotationView *) [self.mapView dequeueReusableAnnotationViewWithIdentifier:identifier3];


        if (annotationView == nil) {
            annotationView = [[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:identifier3];
            annotationView.enabled = YES;
            annotationView.canShowCallout = YES;

        } else {
            annotationView.annotation = annotation;

        } 
...
}

viewForOverlay

 -(MKOverlayView *)mapView:(MKMapView *)mapView viewForOverlay:(id <MKOverlay>)overlay{
        if([overlay isKindOfClass:[MKPolygon class]]){
            MKPolygonView *view = [[MKPolygonView alloc] initWithOverlay:overlay];
            view.lineWidth=1;
            view.strokeColor=[UIColor blueColor];
            view.fillColor=[[UIColor blueColor] colorWithAlphaComponent:0.3];

            recognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(overlayTapped)]; 
            recognizer.delegate=self;
            [view addGestureRecognizer:recognizer];
            [recognizer release];

            return view;
        }
        return nil;
    }


-(void)overlayTapped{

    NSLog(@"overlay tapped");
    //[self.mapView setSelectedAnnotations:?????];
}

Answer 1

I’ve solved whit this code:

After you had determinate the span region

 CLLocation *userLoc = myMapView.userLocation.location;
    CLLocationCoordinate2D userCoordinate = userLoc.coordinate;
    NSLog(@"user latitude = %f",userCoordinate.latitude);
    NSLog(@"user longitude = %f",userCoordinate.longitude);
    myMapView.delegate=self;


    NSMutableArray* annotations=[[NSMutableArray alloc] init];

    //vallee
    CLLocationCoordinate2D theCoordinate1;
    theCoordinate1.latitude = 45.752453;
    theCoordinate1.longitude = 7.642313;
    //venezia
    CLLocationCoordinate2D theCoordinate2;
    theCoordinate2.latitude = 45.442793;
    theCoordinate2.longitude = 12.329691;
    //campione
    CLLocationCoordinate2D theCoordinate3;
    theCoordinate3.latitude = 45.971027;
    theCoordinate3.longitude = 8.971362;
    //sanremo
    CLLocationCoordinate2D theCoordinate4;
    theCoordinate4.latitude = 43.814910;
    theCoordinate4.longitude = 7.772050;

    myAnnotation* myAnnotation1=[[myAnnotation alloc] init];

    myAnnotation1.coordinate=theCoordinate1;
    myAnnotation1.title=@"Casinò della Vallée";
    myAnnotation1.subtitle=@"Saint Vincent";

    myAnnotation* myAnnotation2=[[myAnnotation alloc] init];

    myAnnotation2.coordinate=theCoordinate2;
    myAnnotation2.title=@"Casinò di Venezia";
    myAnnotation2.subtitle=@"Venezia";

    myAnnotation* myAnnotation3=[[myAnnotation alloc] init];

    myAnnotation3.coordinate=theCoordinate3;
    myAnnotation3.title=@"Casinò di Campione";
    myAnnotation3.subtitle=@"Campione";

    myAnnotation* myAnnotation4=[[myAnnotation alloc] init];

    myAnnotation4.coordinate=theCoordinate4;
    myAnnotation4.title=@"Casinò di Sanremo";
    myAnnotation4.subtitle=@"Sanremo";


    [myMapView addAnnotation:myAnnotation1];
    [myMapView addAnnotation:myAnnotation2];
    [myMapView addAnnotation:myAnnotation3];
    [myMapView addAnnotation:myAnnotation4];


    //[annotations addObject:myAnnotation1];
    [annotations addObject:myAnnotation2];
    [annotations addObject:myAnnotation3];
    [annotations addObject:myAnnotation4];


    NSLog(@"%d",[annotations count]);



}

- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id )annotation {
    if (annotation == mapView.userLocation) {
        return nil;
    }
    MKPinAnnotationView *pinView = [[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:@"Pin"];
    pinView.pinColor = MKPinAnnotationColorGreen;
    pinView.canShowCallout = YES;
    pinView.rightCalloutAccessoryView = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];

    pinView.animatesDrop = YES;
    return pinView;
}

//disclosure button con indicazioni
- (void)mapView:(MKMapView *)mapView annotationView:(MKAnnotationView *)view calloutAccessoryControlTapped:(UIControl *)control {

    [self.navigationController pushViewController:[[UIViewController alloc] init] animated:YES];

      //street from here to there

    NSString* addr = [NSString stringWithFormat:@"http://maps.google.com/maps?daddr=%1.6f,%1.6f&saddr=Posizione attuale", view.annotation.coordinate.latitude,view.annotation.coordinate.longitude];

        NSURL* url = [[NSURL alloc] initWithString:[addr stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];  
        [[UIApplication sharedApplication] openURL:url];



}

Wishing this code useful