应用程序因'NSInvalidArgumentException'崩溃，原因：' - [MKAnnotationView setPinColor：]

Question

我的注释代码是：

- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id<MKAnnotation>)annotation {
    static NSString *identifier = @"RoutePinAnnotation";

    if ([annotation isKindOfClass:[UICRouteAnnotation class]]&&[(UICRouteAnnotation *)annotation annotationType] != UICRouteAnnotationTypeWayPoint) 
    {

        MKPinAnnotationView *pinAnnotation = (MKPinAnnotationView *)[mapView dequeueReusableAnnotationViewWithIdentifier:identifier];
        if(!pinAnnotation) {
            pinAnnotation = [[[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:identifier] autorelease];
        }

        if ([(UICRouteAnnotation *)annotation annotationType] == UICRouteAnnotationTypeStart) {

            pinAnnotation.pinColor = MKPinAnnotationColorGreen;


        } else if ([(UICRouteAnnotation *)annotation annotationType] == UICRouteAnnotationTypeEnd) {
            pinAnnotation.pinColor = MKPinAnnotationColorRed;

        }
        pinAnnotation.animatesDrop = YES;
        pinAnnotation.enabled = YES;
        pinAnnotation.canShowCallout = YES;
        return pinAnnotation;
    }





}

应用程序首先运行良好，但是当我们缩放地图时它会崩溃。 由于未捕获的异常 NSInvalidArgumentException 而终止应用，原因：-[MKAnnotationView setPinColor:]
请帮我！！感谢