MapView add an action to custom annotation (the right arrow) - ios

Question

I create the annotation pins via this for loop:
UIButton *eventMore = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
for (i = 0; i < [results count]; i++) {
//NSLog(#"Result: %i = %#", i, results[i]);
//NSLog(#"%#",[[results objectAtIndex:i] objectForKey:#"long"]);
myAnn = [[CustomAnnotation alloc] init];
location.latitude = (double)[[[results objectAtIndex:i] objectForKey:#"lat"] doubleValue];
location.longitude = (double)[[[results objectAtIndex:i] objectForKey:#"long"] doubleValue];
myAnn.coordinate = location;
myAnn.title = [[results objectAtIndex:i] objectForKey:#"title"];
myAnn.subtitle = [[results objectAtIndex:i] objectForKey:#"strap"];
[eventMore addTarget:myAnn action:#selector(btnClicked:) forControlEvents:UIControlEventTouchUpInside];
[locations addObject:myAnn];
//NSLog(#"%i", [[results objectAtIndex:i] objectForKey:#"lat"]);
}
What I am trying to do with this is add the detail disclosure button to the right of the title/description on the annotation however this does not add one in, and all the tuts I have found for this do it using this method - but it isnt working, any advice?
And the code for the action:
-(void)btnClicked:(id)sender{
UIAlertView *btnAlert = [[UIAlertView alloc] initWithTitle:#"title" message:#"msg" delegate:self cancelButtonTitle:#"cancel" otherButtonTitles:nil, nil];
[btnAlert show];
}

Answer 1

You are not setting the CalloutAccessoryView for your annotation.
Sample code
for (i = 0; i < [results count]; i++) {
MKPointAnnotation *myAnn = [[MKPointAnnotation alloc] init];
location.latitude = (double)[[[results objectAtIndex:i] objectForKey:#"lat"] doubleValue];
location.longitude = (double)[[[results objectAtIndex:i] objectForKey:#"long"] doubleValue];
myAnn.coordinate = location;
myAnn.title = [[results objectAtIndex:i] objectForKey:#"title"];
myAnn.subtitle = [[results objectAtIndex:i] objectForKey:#"strap"];
[locations addObject:myAnn];
}
- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation{
static NSString *s = #"ann";
MKAnnotationView *pin = [mapView dequeueReusableAnnotationViewWithIdentifier:s];
if (!pin) {
pin = [[MKPinAnnotationView alloc]initWithAnnotation:annotation reuseIdentifier:s];
pin.canShowCallout = YES;
pin.image = [UIImage imageNamed:#"pin.png"];
pin.calloutOffset = CGPointMake(0, 0);
UIButton *button = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
[button addTarget:self
action:#selector(viewDetails) forControlEvents:UIControlEventTouchUpInside];
pin.rightCalloutAccessoryView = button;
}
return pin;
}