iOS mapview - zoom to pin and then activate callout - ios

Question

I have a mapview in xcode, which is all working well.
What my page does just now is like this:
downloads a bunch of data and locations from a backend database
populates a mapview with locations and drops pins
populates a table underneath the mapview
That all works great, and I end up with a mapview with a load of pins, and a tableview that has the details of those pins.
What I want to do now, is allow the user to tap on a row from the tableview, and have the map zoom and centre to the corresponding map pin, and then automatically activate the annotation pin callout.
In my 'didselectrow' method, I have the following:
MKCoordinateSpan span = MKCoordinateSpanMake(0.1f, 0.1f);
CLLocationCoordinate2D coordinate = { [item.latitude floatValue], [item.longitude floatValue] };
MKCoordinateRegion region = { coordinate, span };
[self.mapView setRegion:region animated:YES];
This works great too. Tapping on the table row will zoom to and centre the map pin at this location.
I just can't get the last step of firing the annotation pin callout to work.
I have tried:
[mapview annotationsInMapRect:mapview.visibleMapRect];
But this isn't working, and it is possible that there still might be 2 or 3 map pins in the visible area.
What I need to do is to get the pin nearest to the centred location (see above - item.latitude / item.longitude) to automatically open it's callout.
Everything in the code is set up and working, and the map pins have callouts that fire when tapped on, I just need this last stage of having the pin nearest the centre location to open automatically.
Can anyone help with this?
I have tried various other suggestions on SO, but none seem to fit this requirement.

Answer 1

I think I have got solution for your problem you need to use this [_mapView setSelectedAnnotations:#[[[self.mapView annotations] lastObject]]];
For testing I have created an small project that have these 2 methods.
- (IBAction)buttonTouched:(id)sender {
[_mapView showAnnotations:[self.mapView annotations] animated:YES];
[self performSelector:#selector(showAnnotationCallOut) withObject:nil afterDelay:1.0f];
}
- (void) showAnnotationCallOut {
[_mapView setSelectedAnnotations:#[[[self.mapView annotations] lastObject]]];
}
Note: I have called just one annotation for test that why I am calling last object. You'll need to call it for specific annotation of your annotation array.
Edit: According to Richerd's comment here is solution for problem of finding the annotion and showing the callout fro that.
for (MapViewAnnotation *annotion in [self.mapView annotion]) {
if ([annotion.identifire isEqualToString:annotationToCallCallOutIdentifier]) {
//[_mapView setSelectedAnnotations:#[annotation]];
[_mapView selectAnnotation:annotation animated:YES];
break;//don't break if there are can be more than one callouts
}
}