MapView Annotation not dragging

Question

I am trying to implement a draggable \"pin\" (actually a custom icon) in a map view. This is the delegate code that I have:

  -(MKAnnotationView *) mapView:(         


        

Answer 1

Use MKPinAnnotationView instead of MKAnnotationView.

MKPinAnnotationView *pin = (MKPinAnnotationView *)[mapView dequeueReusableAnnotationViewWithIdentifier:@"purple_pin"];
if (pin==nil)
{
    pin = [[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:@"purple_pin"];} else {
    pin.annotation=annotation;
} 
pin.pinColor = MKPinAnnotationColorPurple;
pin.draggable = TRUE;
return pin;

Answer 2

This is a tricky one! I've just implemented something similar (though I subclassed MKAnnotationView) and when I tried adding the annotationView:didChange delegate method to my view controller it didn't get called even though I was able to drag the annotation view??

I also copy/pasted your code into my view controller and it worked straight out of the box, with the delegate method being called and all!

The only thing I can think of is that instead of passing mvMap to dequeueReusableAnnotationViewWithIdentifier: try passing the mapView object that is supplied by the delegate method. Based on the code you provided above I am unable to tell if they are the same object so it might be worth a shot?

aView=(MKAnnotationView *) [mvMap dequeueReusableAnnotationViewWithIdentifier:annotation.title];

[EDIT TO ADD MY CODE AS REFERENCE]

- (MKAnnotationView *)mapView:(MKMapView *)theMapView viewForAnnotation:(id<MKAnnotation>)annotation
{
    static NSString* ParkAnnotationIdentifier = @"ParkAnnotationIdentifier";
    MKAnnotationView* parkAnnotationView = (MKAnnotationView *)[mapView dequeueReusableAnnotationViewWithIdentifier:ParkAnnotationIdentifier];
    if (!parkAnnotationView)
    {
        MKAnnotationView *annotationView = [[[MKAnnotationView alloc] initWithAnnotation:annotation
                                                                         reuseIdentifier:ParkAnnotationIdentifier] autorelease];
        UIImage *imageIcon = [UIImage imageNamed:@"scooterIcon.png"];
        annotationView.image = imageIcon;
        annotationView.draggable = YES;
        return annotationView;
    }
    else
    {
        parkAnnotationView.annotation = annotation;
    }
    return parkAnnotationView;
}

Answer 3

Got it! The problem was in the interface file of my custom annotation class. The offending line read:

@property (nonatomic,readonly) CLLocationCoordinate2D   coordinate;

It has to read:

@property (nonatomic,readwrite,assign) CLLocationCoordinate2D   coordinate;

I guess that it has to have read/write capability.

Answer 4

if you are using a subview of MKPinAnnotationView and are overriding setSelected(), make sure you call super.setSelected()