Replacing a calloutaccessoryview in mkannotationview

In my viewForAnnotation delegate, I create a MKAnnotationView with leftCalloutaccessory as a info button. When the info button is tapped, I want to replace it with a UIActivityIndicator. So in the calloutAccessoryTapped delegate, I wrote view.leftCalloutaccessoryView = [UIActivityIndicator indicatorWithStyle:UIActivityIndicatorWhite];

The callout accessory seems to change, but it seems like the view doesn't get updated immediately.

That's when the callout accessory gets hidden (by tapping another pi开发者_JAVA百科n) and is re-opened, I see a spinner. But otherwise, I don't.

I tried calling [view setNeedsdisplay] and [view setNeedsLayout] and [view layoutsubviews] as well but in vain.

Any suggestions/pointers?

I would consider removing and re-adding your annotation. It seems a little heavy handed, but might work.

I was having a similar problem -- I needed to display an image for the leftCalloutAccessoryView if there was one associated with the annotation. Try setting it in mapView:didSelectAnnotationView instead of in mapView:viewForAnnotation

-(void)mapView:(MKMapView *)mapView didSelectAnnotationView:(MKAnnotationView *)annotView
{
    ...

    if(imgURL.length>1){            
        // set a thread that will load the image 
        // but don't set the leftCalloutAccessoryView until the image is loaded 
        dispatch_queue_t downloader = dispatch_queue_create("annotation image downloader",NULL);
        dispatch_async(downloader, ^{
            NSURL* photoURL = [NSURL URLWithString:imgURL];
            NSData* photoData = [NSData dataWithContentsOfURL:photoURL];
            UIImage* photoImage = [UIImage imageWithData:photoData];
            dispatch_async(dispatch_get_main_queue(), ^{
                annotView.leftCalloutAccessoryView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 32, 32)];
                [(UIImageView *) annotView.leftCalloutAccessoryView setImage:photoImage];
            });                
        });
    }
}