Okay, i have a number of pins on the mapkit. These pins showing different types of attractions. (E.g Parks, Farms and etc)

I want to add custom images for these different types of pin. Parks have a park image and vice versa.

However, when i added in, not all the images are showing successfully. For example, in parks, it should have 5 pins, but the image only came up in 2 pins, whereas other 3 is in default red pins.

But if i used colours to differentiate them. For example, [pinsetPinColor:MKPinAnnotationColorGreen];

It works! Anyone knows what is the problem?

Relevant codes below. Tell me if you need more. thanks!

- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation{
if ([annotation isKindOfClass:MKUserLocation.class]) {
    //user location view is being requested,
    //return nil so it uses the default which is a blue dot...
    return nil;
}

//NSLog(@"View for Annotation is called");
MKPinAnnotationView *pin=[[MKPinAnnotationView alloc] 
                          initWithAnnotation:annotation reuseIdentifier:nil];

pin.userInteractionEnabled=TRUE;

MapEvent* event = (MapEvent*)annotation;    
NSLog(@"thetype: %@", event.thetype);


if ([event.thetype isEqualToString:@"adv"]) {
    //[pin setPinColor:MKPinAnnotationColorGreen];
    pin.image = [UIImage imageNamed:@"padv.png"];
}

else if ([event.thetype isEqualToString:@"muse"]){
    //[pin setPinColor:MKPinAnnotationColorPurple];
    pin.image = [UIImage imageNamed:@"pmuse.png"];
}

else if ([event.thetype isEqualToString:@"nightlife"]){
    pin.image = [UIImage imageNamed:@"pnight.png"];

}
else if ([event.thetype isEqualToString:@"parks"]){
    pin.image = [UIImage imageNamed:@"ppark.png"];

}
else if ([event.thetype isEqualToString:@"farms"]){
    pin.image = [UIImage imageNamed:@"pfarm.png"];

}

else {
    [pin setPinColor:MKPinAnnotationColorRed];

}

pin.canShowCallout = YES;
pin.animatesDrop = YES;

UIButton *rightButton = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
[rightButton addTarget:self action:@selector(clickAnnotation:) forControlEvents:UIControlEventTouchUpInside];
[rightButton setTitle:event.uniqueID forState:UIControlStateNormal];

pin.rightCalloutAccessoryView = rightButton;

return pin;

}