Question

Hello and thanks for the help.

I am using the following code to set the pin colors on my MapView annotations ?

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




    MKPinAnnotationView *pinView = (MKPinAnnotationView *)[mapView dequeueReusableAnnotationViewWithIdentifier:@"pinView"];
    if (!pinView) {

        //////////////
        pinView = [[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:@"pinView"];
        pinView.pinColor = MKPinAnnotationColorGreen;
        if([[annotation title] isEqualToString:@"MuRoom"])
        {
            // Do somethingMKAnnotation
            pinView.pinColor = MKPinAnnotationColorRed;

            NSLog( @"data from ann index %@", annTile);
        }
        if([[annotation title] isEqualToString:@"Mike's"])
        {
            // Do somethingMKAnnotation
            pinView.pinColor = MKPinAnnotationColorRed;

            NSLog( @"data from ann index %@", annTile);
        }
        if([[annotation title] isEqualToString:@"Bill's"])
        {
            // Do somethingMKAnnotation
            pinView.pinColor = MKPinAnnotationColorPurple;

            NSLog( @"data from ann index %@", annTile);
        }
        if([[annotation title] isEqualToString:@"Steve's"])
        {
            // Do somethingMKAnnotation
            pinView.pinColor = MKPinAnnotationColorGreen;

            NSLog( @"data from ann index %@", annTile);
        }
        if([[annotation title] isEqualToString:@"Louisa's"])
        {
            // Do somethingMKAnnotation
            pinView.pinColor = MKPinAnnotationColorGreen;

            NSLog( @"data from ann index %@", annTile);
        }


        pinView.animatesDrop = YES;
        pinView.canShowCallout = YES;

        UIButton *rightButton = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
        pinView.rightCalloutAccessoryView = rightButton;
    } else {
        pinView.annotation = annotation;
    }
    return pinView;
}


I am then using the function below to filter my pins locaions



-(void)FilterAddAll:(id)sender
{
    [mapview removeAnnotations:annoArra];
    [mapview removeAnnotations:annoArrayVenue];
 [mapview removeAnnotations:artArray];


//    CLLocationCoordinate2D center = mapview.centerCoordinate;
//    mapview.centerCoordinate = center;


    [mapview addAnnotations:annoArra];
    [mapview addAnnotations:annoArrayVenue];
    [mapview addAnnotations:artArray];

}

-(void)FilterArt:(id)sender
{
    [mapview removeAnnotations:annoArra];
    [mapview removeAnnotations:artArray];
    [mapview removeAnnotations:annoArrayVenue];

    [mapview addAnnotations:annoArra];
}

-(void)FilterVenue:(id)sender
{
    [mapview removeAnnotations:annoArra];
    [mapview removeAnnotations:artArray];
    [mapview removeAnnotations:annoArrayVenue];

    [mapview addAnnotations:artArray];
}

The Question: How do I get the pin colors to retain their original color ? After I filter they come back as random pin colors.

Thanks again.

Answer 1

This occurs because you’re not using the “reuseIdentifier” properly. When you get back a pin from dequeueReusableAnnotationViewWithIdentifier:@”pinView”, you need to either:

always set the pin color, OR
use a different reuseIdentifier for each colored pin

i.e. you might be getting a reusable view with a red pin, and you want to display a blue pin

example:

MKPinAnnotationView *pinView = (MKPinAnnotationView *)[mapView dequeueReusableAnnotationViewWithIdentifier:@"pinView"];
    if (!pinView) {

        //////////////
        pinView = [[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:@"pinView"];

        pinView.animatesDrop = YES;
        pinView.canShowCallout = YES;

        UIButton *rightButton = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
        pinView.rightCalloutAccessoryView = rightButton;
    } else {
        pinView.annotation = annotation;
    }

// SET THE PIN COLOR REGARDLESS OF WHETHER A REUSABLE ANNOTATION WAS RETURNED OR NOT

        pinView.pinColor = MKPinAnnotationColorGreen;
        if([[annotation title] isEqualToString:@"MuRoom"])
        {
            // Do somethingMKAnnotation
            pinView.pinColor = MKPinAnnotationColorRed;

            NSLog( @"data from ann index %@", annTile);
        }
        if([[annotation title] isEqualToString:@"Mike's"])
        {
            // Do somethingMKAnnotation
            pinView.pinColor = MKPinAnnotationColorRed;

            NSLog( @"data from ann index %@", annTile);
        }
        if([[annotation title] isEqualToString:@"Bill's"])
        {
            // Do somethingMKAnnotation
            pinView.pinColor = MKPinAnnotationColorPurple;

            NSLog( @"data from ann index %@", annTile);
        }
        if([[annotation title] isEqualToString:@"Steve's"])
        {
            // Do somethingMKAnnotation
            pinView.pinColor = MKPinAnnotationColorGreen;

            NSLog( @"data from ann index %@", annTile);
        }
        if([[annotation title] isEqualToString:@"Louisa's"])
        {
            // Do somethingMKAnnotation
            pinView.pinColor = MKPinAnnotationColorGreen;

            NSLog( @"data from ann index %@", annTile);
        }