Random MKPointAnnotation in map

Question

In my project I fill my map with these informations

for  (int i = 0; i<arrayResults.count; i++){

        object = [arrayResults objectAtIndex:i];

        if ([[object iden]intValue] == 1) {

            type = @"type_one";

            CLLocationCoordinate2D annotationCoord = CLLocationCoordinate2DMake([[[object coord]objectForKey:@"latitude"] floatValue], [[[object coord]objectForKey:@"longitude"] floatValue]);

            MKPointAnnotation *annotationPoint = [[MKPointAnnotation alloc] init];
            annotationPoint.coordinate = annotationCoord;
            annotationPoint.title = [NSString stringWithFormat:@"%@",[object nome_obj]];
            annotationPoint.subtitle = [NSString stringWithFormat:@"%@",[object address]];
            [map addAnnotation:annotationPoint];
        }

        else if ([[object iden]intValue] == 2) {

          type = @"type_two";

            CLLocationCoordinate2D annotationCoord = CLLocationCoordinate2DMake([[[object coord]objectForKey:@"latitude"] floatValue], [[[object coord]objectForKey:@"longitude"] floatValue]);

            MKPointAnnotation *annotationPoint = [[MKPointAnnotation alloc] init];
            annotationPoint.coordinate = annotationCoord;
            annotationPoint.title = [NSString stringWithFormat:@"%@",[object nome_obj]];
            annotationPoint.subtitle = [NSString stringWithFormat:@"%@",[object address]];
            [map addAnnotation:annotationPoint];
        }

        else if ([[object iden]intValue] == 3) {

            type = @"type_three";

            CLLocationCoordinate2D annotationCoord = CLLocationCoordinate2DMake([[[object coord]objectForKey:@"latitude"] floatValue], [[[object coord]objectForKey:@"longitude"] floatValue]);

            MKPointAnnotation *annotationPoint = [[MKPointAnnotation alloc] init];
            annotationPoint.coordinate = annotationCoord;
            annotationPoint.title = [NSString stringWithFormat:@"%@",[object nome_obj]];
            annotationPoint.subtitle = [NSString stringWithFormat:@"%@",[object address]];
            [map addAnnotation:annotationPoint];
        }

        else if ([[object iden]intValue] == 4) {

            type = @"type_four";

            CLLocationCoordinate2D annotationCoord = CLLocationCoordinate2DMake([[[object coord]objectForKey:@"latitude"] floatValue], [[[object coord]objectForKey:@"longitude"] floatValue]);

            MKPointAnnotation *annotationPoint = [[MKPointAnnotation alloc] init];
            annotationPoint.coordinate = annotationCoord;
            annotationPoint.title = [NSString stringWithFormat:@"%@",[object nome_obj]];
            annotationPoint.subtitle = [NSString stringWithFormat:@"%@",[object address]];
            [map addAnnotation:annotationPoint];
        }

these are four type of object that I add on my map

when I enter inside this method

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

    MKAnnotationView *view = nil;
    if (annotation != mapView.userLocation) {

            if ([[[arrayResults objectAtIndex:countPoint]iden]intValue] == 1){

                view = [mapView dequeueReusableAnnotationViewWithIdentifier:@"type_one"];
                if (!view) {

                    view = [[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:@"type_one"];
                    view.canShowCallout = YES;

                    UIButton* aButton = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
                    [aButton addTarget:self action:@selector(open:) forControlEvents:UIControlEventTouchUpInside];
                    [aButton setTag:countPoint+100];
                    view.rightCalloutAccessoryView = aButton;

                    view.image = [UIImage imageNamed:@"type_one.png"];
                }

            }

            else if ([[[arrayResults objectAtIndex:countPoint]iden]intValue] == 2){

                view = [mapView dequeueReusableAnnotationViewWithIdentifier:@"type_two"];
                if (!view) {

                    view = [[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:@"type_two"];

                    view.canShowCallout = YES;

                    UIButton* aButton = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
                    [aButton addTarget:self action:@selector(open:) forControlEvents:UIControlEventTouchUpInside];
                    [aButton setTag:countPoint+100];
                    view.rightCalloutAccessoryView = aButton;

                    view.image = [UIImage imageNamed:@"type_two.png"];
                }
            }
            else if ([[[arrayResults objectAtIndex:countPoint]iden]intValue] == 3){


                view = [mapView dequeueReusableAnnotationViewWithIdentifier:@"type_three"];
                if (!view) {

                    view = [[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:@"type_three"];

                    view.canShowCallout = YES;

                    UIButton* aButton = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
                    [aButton addTarget:self action:@selector(open:) forControlEvents:UIControlEventTouchUpInside];
                    [aButton setTag:countPoint+100];
                    view.rightCalloutAccessoryView = aButton;

                    view.image = [UIImage imageNamed:@"type_three.png"];
                }

            }
            else if ([[[arrayResults objectAtIndex:countPoint]iden]intValue] == 4){

                view = [mapView dequeueReusableAnnotationViewWithIdentifier:@"type_four"];
                if (!view) {

                    view = [[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:@"type_four"];

                    view.canShowCallout = YES;

                    UIButton* aButton = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
                    [aButton addTarget:self action:@selector(openScheda:) forControlEvents:UIControlEventTouchUpInside];
                    [aButton setTag:countPoint+100];
                    view.rightCalloutAccessoryView = aButton;

                  view.image = [UIImage imageNamed:@"type_four.png"];

                }
            }
countPoint++;
}

The problem is that type of marker don't correspond with array element... but I don't understand. That is if a marker has image "type_one", in the pop up it show "title" of type_four...it don't correspond

Answer 1

Your annotation needs to "know" what type it is so you can create the right kind of view in viewForAnnotation. Do so by subclassing MKPointAnnotation, adding an NSInteger value to it to store the array index.

See MKPointAnnotation add extra property, but you'll add an NSInteger property called index.

When creating your annotations, set this property:

for  (int i = 0; i<arrayResults.count; i++)
{
    object = [arrayResults objectAtIndex:i];

    CLLocationCoordinate2D annotationCoord = CLLocationCoordinate2DMake([[[object coord]objectForKey:@"latitude"] floatValue], [[[object coord]objectForKey:@"longitude"] floatValue]);

    // MKMyPointAnnotation is your MKPointAnnotation subclass
    MKMyPointAnnotation *annotationPoint = [[MKMyPointAnnotation alloc] init];
    annotationPoint.coordinate = annotationCoord;
    annotationPoint.title = [NSString stringWithFormat:@"%@",[object nome_obj]];
    annotationPoint.subtitle = [NSString stringWithFormat:@"%@",[object address]];

    annotationPoint.index = i;                                // store the index

    [map addAnnotation:annotationPoint];
}

Then in your viewForAnnotation, cast the annotation to your subclass, then dereference the type:

- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation {
{
 MKMyPointAnnotation *myAnnotation = (MKMyPointAnnotation *)annotation;
 object = [arrayResults objectAtIndex:myAnnotation.index];      // <-- your index property

 switch ([[object iden] intValue])
 {
  case 1:                                 // type one
    .
    .
    .

 }

.
.
.
}