ios-mapkit, strange behavior with custom image annotations - ios

Question

I've written some code for showing annotations with custom images in a mapview.
My mapview delegate implements this method to customize annotation when they are put in the map:
- (MKAnnotationView *) mapView:(MKMapView *) mapView viewForAnnotation:(id<MKAnnotation>) annotation {
if ([annotation isKindOfClass:[Station class]]) {
Station *current = (Station *)annotation;
MKPinAnnotationView *customPinview = [[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:nil];
if([[current type] compare:FONTANELLA]==NSOrderedSame)
customPinview.pinColor = MKPinAnnotationColorPurple;
else{
int test=current.bici;
if(test==0)
customPinview.image = [UIImage imageNamed:#"bicimir.png"];
else if(test<4)
customPinview.image = [UIImage imageNamed:#"bicimi.png"];
else if(test>=4)
customPinview.image = [UIImage imageNamed:#"bicimig.png"];
}
customPinview.animatesDrop = NO;
customPinview.canShowCallout = YES;
return customPinview;
}
else{
NSString *identifier=#"MyLocation";
MKPinAnnotationView *annotationView = (MKPinAnnotationView *) [_mapView dequeueReusableAnnotationViewWithIdentifier:identifier];
return annotationView;
}
}
The problem is a strange behavior when I long click on a custom annotation on the map:
The image change and the default red pin is shown.
Why this behavior? And How can I avoid it?

Answer 1

When you want to use a custom image for an annotation view, create a generic MKAnnotationView instead of an MKPinAnnotationView.
The MKPinAnnotationView really likes to display its default image which is a pin.
Rearrange the logic a bit so that for FONTANELLA, it creates an MKPinAnnotationView but for the rest an MKAnnotationView.
Also, you should really implement annotation view re-use for all cases (and the last else part doesn't make sense since nothing is done if the dequeue doesn't return anything--you could just do return nil; instead).

Answer 2

inside .h file
#interface AddressAnnotation : NSObject<MKAnnotation> {
CLLocationCoordinate2D coordinate;
NSString *mPinColor;
}
#property (nonatomic, retain) NSString *mPinColor;
#end
in .m file
#implementation AddressAnnotation
#synthesize coordinate mPinColor;
- (NSString *)pincolor{
return mPinColor;
}
- (void) setpincolor:(NSString*) String1{
mPinColor = String1;
}
-(id)initWithCoordinate:(CLLocationCoordinate2D) c{
coordinate=c;
NSLog(#"%f,%f",c.latitude,c.longitude);
return self;
}
#end
inside .m class file
- (MKAnnotationView *) mapView:(MKMapView *)mapView1 viewForAnnotation:(AddressAnnotation *) annotation{
UIImage *anImage=[[UIImage alloc] init];
MKAnnotationView *annView=(MKAnnotationView*)[mapView1 dequeueReusableAnnotationViewWithIdentifier:#"annotation"];
if(annView==nil)
{
annView=[[[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:#"annotation"] autorelease];
}
if([annotation.mPinColor isEqualToString:#"green"])
{
anImage=[UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:#"Google pin green.png" ofType:nil]];
}
else if([annotation.mPinColor isEqualToString:#"red"])
{
anImage=[UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:#"Google pin red.png" ofType:nil]];
}
else if([annotation.mPinColor isEqualToString:#"blue"])
{
anImage=[UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:#"Google pin blue.png" ofType:nil]];
}
annView.image = anImage;
return annView;
}