Getting the bounds of an MKMapView

Question

In order to setup a query to an external server I want to get the bounds of the current Map View in an iPhone app I\'m building. UIView should respond to bounds but it seems

Answer 1

Okay I officially answered my own question but since I didn't find it anywhere before I'll post the answer here:

//To calculate the search bounds...
//First we need to calculate the corners of the map so we get the points
CGPoint nePoint = CGPointMake(self.mapView.bounds.origin.x + mapView.bounds.size.width, mapView.bounds.origin.y);
CGPoint swPoint = CGPointMake((self.mapView.bounds.origin.x), (mapView.bounds.origin.y + mapView.bounds.size.height));

//Then transform those point into lat,lng values
CLLocationCoordinate2D neCoord;
neCoord = [mapView convertPoint:nePoint toCoordinateFromView:mapView];

CLLocationCoordinate2D swCoord;
swCoord = [mapView convertPoint:swPoint toCoordinateFromView:mapView];

Answer 2

Another option is to use the visibleMapRect property on your MKMapView instance and use MKCoordinateForMapPoint() to convert to the lat/lon.

MKMapRect mRect = self.mapView.visibleMapRect;
MKMapPoint neMapPoint = MKMapPointMake(MKMapRectGetMaxX(mRect), mRect.origin.y);
MKMapPoint swMapPoint = MKMapPointMake(mRect.origin.x, MKMapRectGetMaxY(mRect));
CLLocationCoordinate2D neCoord = MKCoordinateForMapPoint(neMapPoint);
CLLocationCoordinate2D swCoord = MKCoordinateForMapPoint(swMapPoint);

Answer 3

I was able to get this to work with the Parse GeoBox query:

//Calculate the corners of the map to get the points
CGPoint nePoint = CGPointMake(self.mapView.bounds.origin.x + self.mapView.bounds.size.width, self.mapView.bounds.origin.y);
CGPoint swPoint = CGPointMake((self.mapView.bounds.origin.x),(self.mapView.bounds.origin.y+ self.mapView.bounds.size.height));

//Transform points into lat/long values
CLLocationCoordinate2D NECoordinate = [self.mapView convertPoint:nePoint toCoordinateFromView:self.mapView];
CLLocationCoordinate2D SWCoordinate = [self.mapView convertPoint:swPoint toCoordinateFromView:self.mapView];

//Convert to Parse GeoPoints
PFGeoPoint *Southwest = [PFGeoPoint geoPointWithLatitude:SWCoordinate.latitude longitude:SWCoordinate.longitude];
PFGeoPoint *Northeast = [PFGeoPoint geoPointWithLatitude:NECoordinate.latitude longitude:NECoordinate.longitude];

Answer 4

this website solve the problem. http://www.softwarepassion.com/how-to-get-geographic-coordinates-of-the-visible-mkmapview-area-in-ios/

MKMapRect mRect = self.mapView.visibleMapRect;

-(CLLocationCoordinate2D)getNECoordinate:(MKMapRect)mRect{
    return [self getCoordinateFromMapRectanglePoint:MKMapRectGetMaxX(mRect) y:mRect.origin.y];
}
-(CLLocationCoordinate2D)getNWCoordinate:(MKMapRect)mRect{
    return [self getCoordinateFromMapRectanglePoint:MKMapRectGetMinX(mRect) y:mRect.origin.y];
}
-(CLLocationCoordinate2D)getSECoordinate:(MKMapRect)mRect{
    return [self getCoordinateFromMapRectanglePoint:MKMapRectGetMaxX(mRect) y:MKMapRectGetMaxY(mRect)];
}
-(CLLocationCoordinate2D)getSWCoordinate:(MKMapRect)mRect{
    return [self getCoordinateFromMapRectanglePoint:mRect.origin.x y:MKMapRectGetMaxY(mRect)];
}

-(CLLocationCoordinate2D)getCoordinateFromMapRectanglePoint:(double)x y:(double)y{
    MKMapPoint swMapPoint = MKMapPointMake(x, y);
    return MKCoordinateForMapPoint(swMapPoint);
}

-(NSArray *)getBoundingBox:(MKMapRect)mRect{
    CLLocationCoordinate2D bottomLeft = [self getSWCoordinate:mRect];
    CLLocationCoordinate2D topRight = [self getNECoordinate:mRect];
    return @[[NSNumber numberWithDouble:bottomLeft.latitude ],
             [NSNumber numberWithDouble:bottomLeft.longitude],
             [NSNumber numberWithDouble:topRight.latitude],
             [NSNumber numberWithDouble:topRight.longitude]];
}