Scale to fit area for all annotations - resulting in scaling between annotations

Question

I had a problem installing all my annotations on the screen ... sometimes it shows all the annotations, but sometimes other applications scale between the two annotations so that none of them are visible ... I want the application to always match the annotation area but not increased between them ... what am I doing wrong?

if ([mapView.annotations count] == 2) { CLLocationCoordinate2D SouthWest = location; CLLocationCoordinate2D NorthEast = savedPosition; NorthEast.latitude = MAX(NorthEast.latitude, savedPosition.latitude); NorthEast.longitude = MAX(NorthEast.longitude, savedPosition.longitude); SouthWest.latitude = MIN(SouthWest.latitude, location.latitude); SouthWest.longitude = MIN(SouthWest.longitude, location.longitude); CLLocation *locSouthWest = [[CLLocation alloc] initWithLatitude:SouthWest.latitude longitude:SouthWest.longitude]; CLLocation *locNorthEast = [[CLLocation alloc] initWithLatitude:NorthEast.latitude longitude:NorthEast.longitude]; CLLocationDistance meter = [locSouthWest distanceFromLocation:locNorthEast]; MKCoordinateRegion region; region.span.latitudeDelta = meter / 111319.5; region.span.longitudeDelta = 0.0; region.center.latitude = (SouthWest.latitude + NorthEast.latitude) / 2.0; region.center.longitude = (SouthWest.longitude + NorthEast.longitude) / 2.0; region = [mapView regionThatFits:region]; [mapView setRegion:region animated:YES]; [locSouthWest release]; [locNorthEast release]; } 

Any ideas?

Thanks!!

Answer 1

Instead:

 region.span.latitudeDelta = meter / 111319.5; region.span.longitudeDelta = 0.0; region.center.latitude = (SouthWest.latitude + NorthEast.latitude) / 2.0; region.center.longitude = (SouthWest.longitude + NorthEast.longitude) / 2.0; 

Try adding:

 region.span.latitudeDelta = fabs(NorthEast.latitude - SouthWest.latitude) * 1.2; region.span.longitudeDelta = fabs(SouthWest.longitude - NorthEast.longitude) * 1.2; region.center.latitude = NorthEast.latitude - (NorthEast.latitude - SouthWest.latitude) * 0.5; region.center.longitude = NorthEast.longitude + (SouthWest.longitude - NorthEast.longitude) * 0.5; 

And removal:

 CLLocationDistance meter = [locSouthWest distanceFromLocation:locNorthEast]; 

Answer 2

Use the following code

 -(void)zoomToFitMapAnnotations:(MKMapView*)mapView{ if([mapView.annotations count] == 0) return; CLLocationCoordinate2D topLeftCoord; topLeftCoord.latitude = -90; topLeftCoord.longitude = 180; CLLocationCoordinate2D bottomRightCoord; bottomRightCoord.latitude = 90; bottomRightCoord.longitude = -180; for(FSMapAnnotation* annotation in mapView.annotations) { topLeftCoord.longitude = fmin(topLeftCoord.longitude, annotation.coordinate.longitude); topLeftCoord.latitude = fmax(topLeftCoord.latitude, annotation.coordinate.latitude); bottomRightCoord.longitude = fmax(bottomRightCoord.longitude, annotation.coordinate.longitude); bottomRightCoord.latitude = fmin(bottomRightCoord.latitude, annotation.coordinate.latitude); } MKCoordinateRegion region; region.center.latitude = topLeftCoord.latitude - (topLeftCoord.latitude - bottomRightCoord.latitude) * 0.5; region.center.longitude = topLeftCoord.longitude + (bottomRightCoord.longitude - topLeftCoord.longitude) * 0.5; region.span.latitudeDelta = fabs(topLeftCoord.latitude - bottomRightCoord.latitude) * 1.1; // Add a little extra space on the sides region.span.longitudeDelta = fabs(bottomRightCoord.longitude - topLeftCoord.longitude) * 1.1; // Add a little extra space on the sides region = [mapView regionThatFits:region]; [mapView setRegion:region animated:YES]; }