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copied!<p>I found a Objective-C answer to this and have translated it for anyone who wants it.</p> <p>To use, place this in a helper class somewhere and call <strong>SetCenterCoordinate</strong>()</p> <p>Source: <a href="http://troybrant.net/blog/2010/01/set-the-zoom-level-of-an-mkmapview/" rel="nofollow">http://troybrant.net/blog/2010/01/set-the-zoom-level-of-an-mkmapview/</a></p> <pre><code>void SetCenterCoordinate (MKMapView MapToCenter, CLLocationCoordinate2D centerCoordinate, int zoomLevel, bool animated) { // clamp large numbers to 28 zoomLevel = Math.Min (zoomLevel, 28); // use the zoom level to compute the region MKCoordinateSpan span = CoordinateSpanWithMapView (MapToCenter, centerCoordinate, zoomLevel); MKCoordinateRegion region = new MKCoordinateRegion (centerCoordinate, span); // set the region like normal MapToCenter.SetRegion (region, animated); } static double MERCATOR_OFFSET = 268435456; static double MERCATOR_RADIUS = 85445659.44705395; double LongitudeToPixelSpaceX (double longitude) { return Math.Round (MERCATOR_OFFSET + MERCATOR_RADIUS * longitude * Math.PI / 180.0); } double LatitudeToPixelSpaceY (double latitude) { return Math.Round (MERCATOR_OFFSET - MERCATOR_RADIUS * Math.Log ((1 + Math.Sin (latitude * Math.PI / 180.0)) / (1 - Math.Sin (latitude * Math.PI / 180.0))) / 2.0); } double PixelSpaceXToLongitude (double pixelX) { return ((Math.Round (pixelX) - MERCATOR_OFFSET) / MERCATOR_RADIUS) * 180.0 / Math.PI; } double PixelSpaceYToLatitude (double pixelY) { return (Math.PI / 2.0 - 2.0 * Math.Tan (Math.Exp ((Math.Round (pixelY) - MERCATOR_OFFSET) / MERCATOR_RADIUS))) * 180.0 / Math.PI; } MKCoordinateSpan CoordinateSpanWithMapView (MKMapView mapView, CLLocationCoordinate2D centerCoordinate, int zoomLevel) { // convert center coordiate to pixel space double centerPixelX = LongitudeToPixelSpaceX (centerCoordinate.Longitude); double centerPixelY = LatitudeToPixelSpaceY (centerCoordinate.Latitude); // determine the scale value from the zoom level int zoomExponent = 20 - zoomLevel; double zoomScale = Math.Pow (2, zoomExponent); // scale the map’s size in pixel space SizeF mapSizeInPixels = mapView.Bounds.Size; double scaledMapWidth = mapSizeInPixels.Width * zoomScale; double scaledMapHeight = mapSizeInPixels.Height; // figure out the position of the top-left pixel double topLeftPixelX = centerPixelX - (scaledMapWidth / 2); double topLeftPixelY = centerPixelY - (scaledMapHeight / 2); // find delta between left and right longitudes double minLng = PixelSpaceXToLongitude (topLeftPixelX); double maxLng = PixelSpaceXToLongitude (topLeftPixelX + scaledMapWidth); double longitudeDelta = maxLng - minLng; // find delta between top and bottom latitudes double minLat = PixelSpaceYToLatitude (topLeftPixelY); double maxLat = PixelSpaceYToLatitude (topLeftPixelY + scaledMapHeight); double latitudeDelta = -1 * (maxLat - minLat); // create and return the lat/lng span MKCoordinateSpan span = new MKCoordinateSpan (latitudeDelta, longitudeDelta); return span; } </code></pre> <p>and another useful one:</p> <pre><code> public static void CenterMapToAnnotations(MKMapView Map, double latlongPadding) { if (Map == null || Map.Annotations == null) return; List<MKAnnotation> annotations = new List<MKAnnotation>(); foreach (var a in Map.Annotations) { annotations.Add(a as MKAnnotation); } if (annotations.Count > 1) { double maxLat = annotations.OrderByDescending (e => e.Coordinate.Latitude).FirstOrDefault ().Coordinate.Latitude; double maxLong = annotations.OrderByDescending (e => e.Coordinate.Longitude).FirstOrDefault ().Coordinate.Longitude; double minLat = annotations.OrderBy (e => e.Coordinate.Latitude).FirstOrDefault ().Coordinate.Latitude; double minLong = annotations.OrderBy (e => e.Coordinate.Longitude).FirstOrDefault ().Coordinate.Longitude; MKCoordinateRegion region = new MKCoordinateRegion (); region.Center.Latitude = (maxLat + minLat) / 2; region.Center.Longitude = (maxLong + minLong) / 2; region.Span.LatitudeDelta = maxLat - minLat+latlongPadding ; region.Span.LongitudeDelta = maxLong - minLong+latlongPadding; Map.Region = region; } } </code></pre>

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