How to resize MKAnnotationView on iOS6?

Question

Resize MKAnnotationView Image When map zooms in and out? This methord are successful on iOS5, but failed on iOS6.

I change the MKAnnotationView's transform directly, and no luck. The MKAnnotationView only resize in a flash(When touch up inside the MKMapView, after the touch up finish, the MKAnnotationView will restore the original size).

My code are below:

- (void)mapView:(MKMapView *)mapView regionDidChangeAnimated:(BOOL)animated {
for (id <MKAnnotation>annotation in _mapView.annotations) {
    // if it's the user location, just return nil.
    if ([annotation isKindOfClass:[MKUserLocation class]])
        continue;

    // handle our custom annotations
    //
    if ([annotation isKindOfClass:[XPMKAnnotation class]])
    {
        // try to retrieve an existing pin view first
        MKAnnotationView *pinView = [_mapView viewForAnnotation:annotation];
        //resize the pin view
        double zoomLevel = [_mapView getZoomLevel];
        double scale = (1.0 * zoomLevel / 16) + 0.5;
        pinView.transform = CGAffineTransformMakeScale(scale, scale);
    }
    }
}

Can we resize the MKAnnotationView on iOS6? Anybody know any way?

Bedad

Having that same issue here. Mine looks like it's flickering, as if the transform keeps getting reset for the AnnotationView. Will post here if I find a solution. – Maus

Answer 1

Apple suggests resizing the .image property of an annotation view. In my case shown below, I looked at the UIImage that was set in the viewforAnnotation and re-scaled it to the zoom level in a UIPinchGestureRecognizer

   UIImage *orangeImage = [UIImage imageNamed:@"Orange210.PNG"];
    CGRect resizeRect;
    //rescale image based on zoom level
    resizeRect.size.height = orangeImage.size.height * scale;
    resizeRect.size.width = orangeImage.size.width  * scale ;
    NSLog(@"height =  %f, width = %f, zoomLevel = %f", resizeRect.size.height, resizeRect.size.width,zoomLevel );
    resizeRect.origin = (CGPoint){0,0};
    UIGraphicsBeginImageContext(resizeRect.size);
    [orangeImage drawInRect:resizeRect];
    UIImage *resizedImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    pinView.image = resizedImage;

Macroscopic

Thank Erik Gross, very help for me. – Bedad

FYI, getZoom is from a category discussed here: #7657707 – Adventuress

what is the Scale here – Edh

Vishnu and @Quincy. You can find the definition of scale from the question pointed in first line of this question. See the answer – Satanic

I have implemented the same but my image is not resizing. – Satanic