MKAnnotationView pin.image incorrect image displayed - ios

Question

I'm having trouble understanding what I'm doing wrong when setting my custom pin images.
Here is my mapView:viewForAnnotation method that I have. As you can see, I want different images to display based on the value in my Location object. For the majority this works, and the correct images are being associated with the correct pins. However, on occasion they are just plain wrong and seem to be randomly assigned.
Any guidance would be appreciated!
EDIT: I've updated my code below in line with latest comments. It's still causing the same behaviour....
- (MKAnnotationView *)mapView:(MKMapView *)MapView viewForAnnotation:(id <MKAnnotation>)annotation
{
if ([annotation isKindOfClass:[MKUserLocation class]])
{
return nil;
}
if([annotation isKindOfClass:[ADClusterAnnotation class]])
{
MKAnnotationView * pinView = (MKAnnotationView *)[MapView dequeueReusableAnnotationViewWithIdentifier:#"ADClusterableAnnotation"];
if (pinView == nil)
{
pinView = [[MKAnnotationView alloc] initWithAnnotation:annotation
reuseIdentifier:#"ADClusterableAnnotation"];
} else
{
pinView.annotation = annotation;
}
Location *selectedLocation = [[[(ADClusterAnnotation *) annotation cluster] annotation] annotation];
UIButton *rightCallout = [UIButton buttonWithType:UIButtonTypeCustom];
rightCallout.frame = CGRectMake(0, 0, 23, 23);
rightCallout.contentVerticalAlignment = UIControlContentVerticalAlignmentCenter;
rightCallout.contentHorizontalAlignment = UIControlContentHorizontalAlignmentCenter;
pinView.image = nil;
pinView.canShowCallout = YES;
[rightCallout setImage:[UIImage imageNamed:#"star.png"] forState:UIControlStateNormal];
pinView.rightCalloutAccessoryView = rightCallout;
if (selectedLocation.number.intValue > 4)
{
pinView.image = [UIImage imageNamed:#"image3.png"];
}
else if (selectedLocation.number.intValue >= 1)
{
pinView.image = [UIImage imageNamed:#"image2.png"];
}
else if (selectedLocation.number.intValue < 1)
{
pinView.image = [UIImage imageNamed:#"image3.png"];
}
return pinView;
}
return nil;
}
OK. I've made it much simpler than the starting point, but I've still got the exact same problem! It's is really driving me crazy, I have no idea what I'm doing wrong. Please please can someone help.
btw, I'm using the following for clustering my annotations (I don't know if this is causing issue!): https://github.com/applidium/ADClusterMapView

Answer 1

You are only setting the pinView.image if pinView is hill after trying to dequeue it. Which will work for the first few until the page is full. If you then scroll down the ones on screen go out of view and get reused for the new rows that appear. Because they are pulled from the queue you are not changing their image and you see the image from the rows that have gone away.
Basically you should build a new pinView if you can't dequeue one, but you still need to set the pinView.image either way, so close off the if statement like this.
if (!pinView) {
pinView = [[MKAnnotationView alloc] initWithAnnotation:annotation
} reuseIdentifier:#"ADClusterableAnnotation"];