Objective c 用于存储数据库URL的自定义注释属性（继承问题？）

我的注释放置在地图上，如下所示：

for (i = 0; i < [results count]; i++) {
        // create new object CustomAnnotation
        myAnn = [[CustomAnnotation alloc] init];
        // set the lat and long of the object
        location.latitude = (double)[[[results objectAtIndex:i] objectForKey:@"lat"] doubleValue];
        location.longitude = (double)[[[results objectAtIndex:i] objectForKey:@"long"] doubleValue];
        // set properties of the object
        myAnn.coordinate = location;
        myAnn.title = [[results objectAtIndex:i] objectForKey:@"title"];
        myAnn.subtitle = [[results objectAtIndex:i] objectForKey:@"strap"];
        myAnn.pinId = [[results objectAtIndex:i] objectForKey:@"id"];
        myAnn.url = [[results objectAtIndex:i] objectForKey:@"link"];
        myAnn.dateTime = [[results objectAtIndex:i] objectForKey:@"timestamp"];

        // add the object to the array locations
        [locations addObject:myAnn];
    }

但是，我无法访问view.annotation.url，这很糟糕。有没有办法获取myAnn的url值？myAnn是一个对象CustomAnnotation（其中定义了@property url之类的内容），它具有：

@interface CustomAnnotation : NSObject <MKAnnotation>

@接口自定义注释：NSObject

我希望view.annotation.url会被继承，但再看看，我并没有访问

CustomAnnotation

因此，我的问题是，当单击“详细信息披露”按钮时，我可以获得注释的url吗？

简单：

- (void)mapView:(MKMapView *)mapView annotationView:(MKAnnotationView *)view calloutAccessoryControlTapped:(UIControl *)control {
    CustomAnnotation *annotation = (CustomAnnotation *)view.annotation;
    NSURL *selectedURL = annotation.url;
}

- (void)mapView:(MKMapView *)mapView annotationView:(MKAnnotationView *)view calloutAccessoryControlTapped:(UIControl *)control {
    CustomAnnotation *annotation = (CustomAnnotation *)view.annotation;
    NSURL *selectedURL = annotation.url;
}