问在开始时可靠地选择MKMapView中的一个概念(在ios 6和IOS5.1中)？

EN

@interface MapViewController : UIViewController<MKMapViewDelegate>
...
- (void) viewWillAppear:(BOOL)animated
{
  [self displayAnnotations];
}

- (void) viewDidAppear:(BOOL)animated
{
    ...
    // Zoom in to event
    [map setRegion:region animated:YES];        
}

- (void) mapView:(MKMapView *)mapView regionDidChangeAnimated:(BOOL)animated
{
   ...
   regionAnimationEnded = YES;
   [self selectAnnotation:a];
   ...
}

- (void)mapView:(MKMapView *)mapView didAddAnnotationViews:(NSArray *)views
{
   ...
   // check to see if the right view is in the array
   ...
   annotationViewDidAppear = YES;
   [self selectAnnotation:a];
   ...   
}

- (void) selectAnnotation:(id<MKAnnotation>)annotation
{
   if(annotationViewDidAppear && regionAnimationEnded)
   {
     if(!openedAnnotationFirstTime)
     {
        [map selectAnnotation:annotation animated:YES];
        openedAnnotationFirstTime = YES;
     }
   }
}