Wanted: How to reliably, consistently select an MKMapView annotation

After calling MKMapView's setCenterCoordinate:animated: method (without animation), I'd like to call selectAnnotation:animated: (with animation) so that the annotation pops out from the newly-centered pushpin.

For now, I simply watch for mapViewDidFinishLoadingMap: and then select the annotation. However, this is problematic. For instance, this method isn't called when there's no need to load additional map data. In those cases, my annotation isn't selected. :(

Very well. I could call this immediately after setting the center coordinate instead. Ahh, but in that case it's possible that there is map data to load (but it hasn't finished loading yet). I'd risk calling it too soon, with the animation becoming spotty at best.

Thus, if I understand correctly, it's not a matter of knowing if my coordinate is visible, since it's possible to stray almost a screenful of distance and have to load new map data. Rather, it's a matter of knowing if new map data needs to be loaded, and then acting accordingly.

Any ideas on how to accomplish this, or how to otherwise (reliably) select an annotation after re-centering the map view on the coordinate where that annotation lives?

Clues appreciated - thanks!

ios mapkit mkpinannotationview

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I was having a similar problem. I was using the default MKPinAnnotationView with animatesDrop:YES. After I added the annotations to the MKMapView, I was doing this:

[mapView selectAnnotation:[mapView.annotations objectAtIndex:1] animated:YES]

which in the logic of my program, should select the nearest annotation. This wasn't working. I figured out the reason: the annotation view was not on the screen at the time of this select call, because of the pin drop animation. So all I did was set a timer to select the annotation a second later. It's a hack, but it works. I'm not sure if it'll work in every situation though, for instance on a 3G vs. 3Gs. It'd be better to figure out the right callback function to put it in.

selectTimer = [NSTimer scheduledTimerWithTimeInterval:1 target:self
               selector:@selector(selectClosestAnnotation) userInfo:nil
               repeats:NO];

- (void)selectClosestAnnotation {
    [mapView selectAnnotation:[mapView.annotations objectAtIndex:1]
             animated:YES];
}

answered 2009-12-15T17:49:23.100

Wanted: How to reliably, consistently select an MKMapView annotation

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